diff --git a/.clang-tidy.hash b/.clang-tidy.hash
index 9661c2ca02..0a272d21ba 100644
--- a/.clang-tidy.hash
+++ b/.clang-tidy.hash
@@ -1 +1 @@
-d272a88e8ca28ae9340a9a03295a566432a52cb696501908f57764475bf7ca65
+15dc295268b2dcf75942f42759b3ddec64eba89f75525698eb39c95a7f4b14ce
diff --git a/.github/workflows/sync-device-classes.yml b/.github/workflows/sync-device-classes.yml
index 8c830d99c7..97fbf7aa9e 100644
--- a/.github/workflows/sync-device-classes.yml
+++ b/.github/workflows/sync-device-classes.yml
@@ -41,7 +41,7 @@ jobs:
           python script/run-in-env.py pre-commit run --all-files
 
       - name: Commit changes
-        uses: peter-evans/create-pull-request@98357b18bf14b5342f975ff684046ec3b2a07725 # v8.0.0
+        uses: peter-evans/create-pull-request@c0f553fe549906ede9cf27b5156039d195d2ece0 # v8.1.0
         with:
           commit-message: "Synchronise Device Classes from Home Assistant"
           committer: esphomebot <esphome@openhomefoundation.org>
diff --git a/esphome/__main__.py b/esphome/__main__.py
index 545464be10..55297e8d9b 100644
--- a/esphome/__main__.py
+++ b/esphome/__main__.py
@@ -1,5 +1,6 @@
 # PYTHON_ARGCOMPLETE_OK
 import argparse
+from collections.abc import Callable
 from datetime import datetime
 import functools
 import getpass
@@ -42,6 +43,7 @@ from esphome.const import (
     CONF_SUBSTITUTIONS,
     CONF_TOPIC,
     ENV_NOGITIGNORE,
+    KEY_NATIVE_IDF,
     PLATFORM_ESP32,
     PLATFORM_ESP8266,
     PLATFORM_RP2040,
@@ -115,6 +117,7 @@ class ArgsProtocol(Protocol):
     configuration: str
     name: str
     upload_speed: str | None
+    native_idf: bool
 
 
 def choose_prompt(options, purpose: str = None):
@@ -499,12 +502,15 @@ def wrap_to_code(name, comp):
     return wrapped
 
 
-def write_cpp(config: ConfigType) -> int:
+def write_cpp(config: ConfigType, native_idf: bool = False) -> int:
     if not get_bool_env(ENV_NOGITIGNORE):
         writer.write_gitignore()
 
+    # Store native_idf flag so esp32 component can check it
+    CORE.data[KEY_NATIVE_IDF] = native_idf
+
     generate_cpp_contents(config)
-    return write_cpp_file()
+    return write_cpp_file(native_idf=native_idf)
 
 
 def generate_cpp_contents(config: ConfigType) -> None:
@@ -518,32 +524,54 @@ def generate_cpp_contents(config: ConfigType) -> None:
     CORE.flush_tasks()
 
 
-def write_cpp_file() -> int:
+def write_cpp_file(native_idf: bool = False) -> int:
     code_s = indent(CORE.cpp_main_section)
     writer.write_cpp(code_s)
 
-    from esphome.build_gen import platformio
+    if native_idf and CORE.is_esp32 and CORE.target_framework == "esp-idf":
+        from esphome.build_gen import espidf
 
-    platformio.write_project()
+        espidf.write_project()
+    else:
+        from esphome.build_gen import platformio
+
+        platformio.write_project()
 
     return 0
 
 
 def compile_program(args: ArgsProtocol, config: ConfigType) -> int:
-    from esphome import platformio_api
+    native_idf = getattr(args, "native_idf", False)
 
     # NOTE: "Build path:" format is parsed by script/ci_memory_impact_extract.py
     # If you change this format, update the regex in that script as well
     _LOGGER.info("Compiling app... Build path: %s", CORE.build_path)
-    rc = platformio_api.run_compile(config, CORE.verbose)
-    if rc != 0:
-        return rc
+
+    if native_idf and CORE.is_esp32 and CORE.target_framework == "esp-idf":
+        from esphome import espidf_api
+
+        rc = espidf_api.run_compile(config, CORE.verbose)
+        if rc != 0:
+            return rc
+
+        # Create factory.bin and ota.bin
+        espidf_api.create_factory_bin()
+        espidf_api.create_ota_bin()
+    else:
+        from esphome import platformio_api
+
+        rc = platformio_api.run_compile(config, CORE.verbose)
+        if rc != 0:
+            return rc
+
+        idedata = platformio_api.get_idedata(config)
+        if idedata is None:
+            return 1
 
     # Check if firmware was rebuilt and emit build_info + create manifest
     _check_and_emit_build_info()
 
-    idedata = platformio_api.get_idedata(config)
-    return 0 if idedata is not None else 1
+    return 0
 
 
 def _check_and_emit_build_info() -> None:
@@ -800,7 +828,8 @@ def command_vscode(args: ArgsProtocol) -> int | None:
 
 
 def command_compile(args: ArgsProtocol, config: ConfigType) -> int | None:
-    exit_code = write_cpp(config)
+    native_idf = getattr(args, "native_idf", False)
+    exit_code = write_cpp(config, native_idf=native_idf)
     if exit_code != 0:
         return exit_code
     if args.only_generate:
@@ -855,7 +884,8 @@ def command_logs(args: ArgsProtocol, config: ConfigType) -> int | None:
 
 
 def command_run(args: ArgsProtocol, config: ConfigType) -> int | None:
-    exit_code = write_cpp(config)
+    native_idf = getattr(args, "native_idf", False)
+    exit_code = write_cpp(config, native_idf=native_idf)
     if exit_code != 0:
         return exit_code
     exit_code = compile_program(args, config)
@@ -936,11 +966,21 @@ def command_dashboard(args: ArgsProtocol) -> int | None:
     return dashboard.start_dashboard(args)
 
 
-def command_update_all(args: ArgsProtocol) -> int | None:
+def run_multiple_configs(
+    files: list, command_builder: Callable[[str], list[str]]
+) -> int:
+    """Run a command for each configuration file in a subprocess.
+
+    Args:
+        files: List of configuration files to process.
+        command_builder: Callable that takes a file path and returns a command list.
+
+    Returns:
+        Number of failed files.
+    """
     import click
 
     success = {}
-    files = list_yaml_files(args.configuration)
     twidth = 60
 
     def print_bar(middle_text):
@@ -950,17 +990,19 @@ def command_update_all(args: ArgsProtocol) -> int | None:
         safe_print(f"{half_line}{middle_text}{half_line}")
 
     for f in files:
-        safe_print(f"Updating {color(AnsiFore.CYAN, str(f))}")
+        f_path = Path(f) if not isinstance(f, Path) else f
+
+        if any(f_path.name == x for x in SECRETS_FILES):
+            _LOGGER.warning("Skipping secrets file %s", f_path)
+            continue
+
+        safe_print(f"Processing {color(AnsiFore.CYAN, str(f))}")
         safe_print("-" * twidth)
         safe_print()
-        if CORE.dashboard:
-            rc = run_external_process(
-                "esphome", "--dashboard", "run", f, "--no-logs", "--device", "OTA"
-            )
-        else:
-            rc = run_external_process(
-                "esphome", "run", f, "--no-logs", "--device", "OTA"
-            )
+
+        cmd = command_builder(f)
+        rc = run_external_process(*cmd)
+
         if rc == 0:
             print_bar(f"[{color(AnsiFore.BOLD_GREEN, 'SUCCESS')}] {str(f)}")
             success[f] = True
@@ -975,6 +1017,8 @@ def command_update_all(args: ArgsProtocol) -> int | None:
     print_bar(f"[{color(AnsiFore.BOLD_WHITE, 'SUMMARY')}]")
     failed = 0
     for f in files:
+        if f not in success:
+            continue  # Skipped file
         if success[f]:
             safe_print(f"  - {str(f)}: {color(AnsiFore.GREEN, 'SUCCESS')}")
         else:
@@ -983,6 +1027,17 @@ def command_update_all(args: ArgsProtocol) -> int | None:
     return failed
 
 
+def command_update_all(args: ArgsProtocol) -> int | None:
+    files = list_yaml_files(args.configuration)
+
+    def build_command(f):
+        if CORE.dashboard:
+            return ["esphome", "--dashboard", "run", f, "--no-logs", "--device", "OTA"]
+        return ["esphome", "run", f, "--no-logs", "--device", "OTA"]
+
+    return run_multiple_configs(files, build_command)
+
+
 def command_idedata(args: ArgsProtocol, config: ConfigType) -> int:
     import json
 
@@ -1284,6 +1339,11 @@ def parse_args(argv):
         help="Only generate source code, do not compile.",
         action="store_true",
     )
+    parser_compile.add_argument(
+        "--native-idf",
+        help="Build with native ESP-IDF instead of PlatformIO (ESP32 esp-idf framework only).",
+        action="store_true",
+    )
 
     parser_upload = subparsers.add_parser(
         "upload",
@@ -1365,6 +1425,11 @@ def parse_args(argv):
         help="Reset the device before starting serial logs.",
         default=os.getenv("ESPHOME_SERIAL_LOGGING_RESET"),
     )
+    parser_run.add_argument(
+        "--native-idf",
+        help="Build with native ESP-IDF instead of PlatformIO (ESP32 esp-idf framework only).",
+        action="store_true",
+    )
 
     parser_clean = subparsers.add_parser(
         "clean-mqtt",
@@ -1533,38 +1598,48 @@ def run_esphome(argv):
 
     _LOGGER.info("ESPHome %s", const.__version__)
 
-    for conf_path in args.configuration:
-        conf_path = Path(conf_path)
-        if any(conf_path.name == x for x in SECRETS_FILES):
-            _LOGGER.warning("Skipping secrets file %s", conf_path)
-            continue
+    # Multiple configurations: use subprocesses to avoid state leakage
+    # between compilations (e.g., LVGL touchscreen state in module globals)
+    if len(args.configuration) > 1:
+        # Build command by reusing argv, replacing all configs with single file
+        # argv[0] is the program path, skip it since we prefix with "esphome"
+        def build_command(f):
+            return (
+                ["esphome"]
+                + [arg for arg in argv[1:] if arg not in args.configuration]
+                + [str(f)]
+            )
 
-        CORE.config_path = conf_path
-        CORE.dashboard = args.dashboard
+        return run_multiple_configs(args.configuration, build_command)
 
-        # For logs command, skip updating external components
-        skip_external = args.command == "logs"
-        config = read_config(
-            dict(args.substitution) if args.substitution else {},
-            skip_external_update=skip_external,
-        )
-        if config is None:
-            return 2
-        CORE.config = config
+    # Single configuration
+    conf_path = Path(args.configuration[0])
+    if any(conf_path.name == x for x in SECRETS_FILES):
+        _LOGGER.warning("Skipping secrets file %s", conf_path)
+        return 0
 
-        if args.command not in POST_CONFIG_ACTIONS:
-            safe_print(f"Unknown command {args.command}")
+    CORE.config_path = conf_path
+    CORE.dashboard = args.dashboard
 
-        try:
-            rc = POST_CONFIG_ACTIONS[args.command](args, config)
-        except EsphomeError as e:
-            _LOGGER.error(e, exc_info=args.verbose)
-            return 1
-        if rc != 0:
-            return rc
+    # For logs command, skip updating external components
+    skip_external = args.command == "logs"
+    config = read_config(
+        dict(args.substitution) if args.substitution else {},
+        skip_external_update=skip_external,
+    )
+    if config is None:
+        return 2
+    CORE.config = config
 
-        CORE.reset()
-    return 0
+    if args.command not in POST_CONFIG_ACTIONS:
+        safe_print(f"Unknown command {args.command}")
+        return 1
+
+    try:
+        return POST_CONFIG_ACTIONS[args.command](args, config)
+    except EsphomeError as e:
+        _LOGGER.error(e, exc_info=args.verbose)
+        return 1
 
 
 def main():
diff --git a/esphome/build_gen/espidf.py b/esphome/build_gen/espidf.py
new file mode 100644
index 0000000000..f45efb82c1
--- /dev/null
+++ b/esphome/build_gen/espidf.py
@@ -0,0 +1,139 @@
+"""ESP-IDF direct build generator for ESPHome."""
+
+import json
+from pathlib import Path
+
+from esphome.components.esp32 import get_esp32_variant
+from esphome.core import CORE
+from esphome.helpers import mkdir_p, write_file_if_changed
+
+
+def get_available_components() -> list[str] | None:
+    """Get list of available ESP-IDF components from project_description.json.
+
+    Returns only internal ESP-IDF components, excluding external/managed
+    components (from idf_component.yml).
+    """
+    project_desc = Path(CORE.build_path) / "build" / "project_description.json"
+    if not project_desc.exists():
+        return None
+
+    try:
+        with open(project_desc, encoding="utf-8") as f:
+            data = json.load(f)
+
+        component_info = data.get("build_component_info", {})
+
+        result = []
+        for name, info in component_info.items():
+            # Exclude our own src component
+            if name == "src":
+                continue
+
+            # Exclude managed/external components
+            comp_dir = info.get("dir", "")
+            if "managed_components" in comp_dir:
+                continue
+
+            result.append(name)
+
+        return result
+    except (json.JSONDecodeError, OSError):
+        return None
+
+
+def has_discovered_components() -> bool:
+    """Check if we have discovered components from a previous configure."""
+    return get_available_components() is not None
+
+
+def get_project_cmakelists() -> str:
+    """Generate the top-level CMakeLists.txt for ESP-IDF project."""
+    # Get IDF target from ESP32 variant (e.g., ESP32S3 -> esp32s3)
+    variant = get_esp32_variant()
+    idf_target = variant.lower().replace("-", "")
+
+    return f"""\
+# Auto-generated by ESPHome
+cmake_minimum_required(VERSION 3.16)
+
+set(IDF_TARGET {idf_target})
+set(EXTRA_COMPONENT_DIRS ${{CMAKE_SOURCE_DIR}}/src)
+
+include($ENV{{IDF_PATH}}/tools/cmake/project.cmake)
+project({CORE.name})
+"""
+
+
+def get_component_cmakelists(minimal: bool = False) -> str:
+    """Generate the main component CMakeLists.txt."""
+    idf_requires = [] if minimal else (get_available_components() or [])
+    requires_str = " ".join(idf_requires)
+
+    # Extract compile definitions from build flags (-DXXX -> XXX)
+    compile_defs = [flag[2:] for flag in CORE.build_flags if flag.startswith("-D")]
+    compile_defs_str = "\n    ".join(compile_defs) if compile_defs else ""
+
+    # Extract compile options (-W flags, excluding linker flags)
+    compile_opts = [
+        flag
+        for flag in CORE.build_flags
+        if flag.startswith("-W") and not flag.startswith("-Wl,")
+    ]
+    compile_opts_str = "\n    ".join(compile_opts) if compile_opts else ""
+
+    # Extract linker options (-Wl, flags)
+    link_opts = [flag for flag in CORE.build_flags if flag.startswith("-Wl,")]
+    link_opts_str = "\n    ".join(link_opts) if link_opts else ""
+
+    return f"""\
+# Auto-generated by ESPHome
+file(GLOB_RECURSE app_sources
+    "${{CMAKE_CURRENT_SOURCE_DIR}}/*.cpp"
+    "${{CMAKE_CURRENT_SOURCE_DIR}}/*.c"
+    "${{CMAKE_CURRENT_SOURCE_DIR}}/esphome/*.cpp"
+    "${{CMAKE_CURRENT_SOURCE_DIR}}/esphome/*.c"
+)
+
+idf_component_register(
+    SRCS ${{app_sources}}
+    INCLUDE_DIRS "." "esphome"
+    REQUIRES {requires_str}
+)
+
+# Apply C++ standard
+target_compile_features(${{COMPONENT_LIB}} PUBLIC cxx_std_20)
+
+# ESPHome compile definitions
+target_compile_definitions(${{COMPONENT_LIB}} PUBLIC
+    {compile_defs_str}
+)
+
+# ESPHome compile options
+target_compile_options(${{COMPONENT_LIB}} PUBLIC
+    {compile_opts_str}
+)
+
+# ESPHome linker options
+target_link_options(${{COMPONENT_LIB}} PUBLIC
+    {link_opts_str}
+)
+"""
+
+
+def write_project(minimal: bool = False) -> None:
+    """Write ESP-IDF project files."""
+    mkdir_p(CORE.build_path)
+    mkdir_p(CORE.relative_src_path())
+
+    # Write top-level CMakeLists.txt
+    write_file_if_changed(
+        CORE.relative_build_path("CMakeLists.txt"),
+        get_project_cmakelists(),
+    )
+
+    # Write component CMakeLists.txt in src/
+    write_file_if_changed(
+        CORE.relative_src_path("CMakeLists.txt"),
+        get_component_cmakelists(minimal=minimal),
+    )
diff --git a/esphome/codegen.py b/esphome/codegen.py
index 6d55c6023d..4a2a5975c6 100644
--- a/esphome/codegen.py
+++ b/esphome/codegen.py
@@ -69,6 +69,7 @@ from esphome.cpp_types import (  # noqa: F401
     JsonObjectConst,
     Parented,
     PollingComponent,
+    StringRef,
     arduino_json_ns,
     bool_,
     const_char_ptr,
diff --git a/esphome/components/adc/sensor.py b/esphome/components/adc/sensor.py
index 607609bbc7..64dd22b0c3 100644
--- a/esphome/components/adc/sensor.py
+++ b/esphome/components/adc/sensor.py
@@ -160,21 +160,21 @@ async def to_code(config):
         zephyr_add_user("io-channels", f"<&adc {channel_id}>")
         zephyr_add_overlay(
             f"""
-&adc {{
-    #address-cells = <1>;
-    #size-cells = <0>;
+                &adc {{
+                    #address-cells = <1>;
+                    #size-cells = <0>;
 
-    channel@{channel_id} {{
-        reg = <{channel_id}>;
-        zephyr,gain = "{gain}";
-        zephyr,reference = "ADC_REF_INTERNAL";
-        zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
-        zephyr,input-positive = <NRF_SAADC_{pin_number}>;
-        zephyr,resolution = <14>;
-        zephyr,oversampling = <8>;
-    }};
-}};
-"""
+                    channel@{channel_id} {{
+                        reg = <{channel_id}>;
+                        zephyr,gain = "{gain}";
+                        zephyr,reference = "ADC_REF_INTERNAL";
+                        zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
+                        zephyr,input-positive = <NRF_SAADC_{pin_number}>;
+                        zephyr,resolution = <14>;
+                        zephyr,oversampling = <8>;
+                    }};
+                }};
+            """
         )
 
 
diff --git a/esphome/components/alarm_control_panel/alarm_control_panel.cpp b/esphome/components/alarm_control_panel/alarm_control_panel.cpp
index 248b5065ad..ab0a780cef 100644
--- a/esphome/components/alarm_control_panel/alarm_control_panel.cpp
+++ b/esphome/components/alarm_control_panel/alarm_control_panel.cpp
@@ -67,52 +67,29 @@ void AlarmControlPanel::add_on_ready_callback(std::function<void()> &&callback)
   this->ready_callback_.add(std::move(callback));
 }
 
-void AlarmControlPanel::arm_away(optional<std::string> code) {
+void AlarmControlPanel::arm_with_code_(AlarmControlPanelCall &(AlarmControlPanelCall::*arm_method)(),
+                                       const char *code) {
   auto call = this->make_call();
-  call.arm_away();
-  if (code.has_value())
-    call.set_code(code.value());
+  (call.*arm_method)();
+  if (code != nullptr)
+    call.set_code(code);
   call.perform();
 }
 
-void AlarmControlPanel::arm_home(optional<std::string> code) {
-  auto call = this->make_call();
-  call.arm_home();
-  if (code.has_value())
-    call.set_code(code.value());
-  call.perform();
+void AlarmControlPanel::arm_away(const char *code) { this->arm_with_code_(&AlarmControlPanelCall::arm_away, code); }
+
+void AlarmControlPanel::arm_home(const char *code) { this->arm_with_code_(&AlarmControlPanelCall::arm_home, code); }
+
+void AlarmControlPanel::arm_night(const char *code) { this->arm_with_code_(&AlarmControlPanelCall::arm_night, code); }
+
+void AlarmControlPanel::arm_vacation(const char *code) {
+  this->arm_with_code_(&AlarmControlPanelCall::arm_vacation, code);
 }
 
-void AlarmControlPanel::arm_night(optional<std::string> code) {
-  auto call = this->make_call();
-  call.arm_night();
-  if (code.has_value())
-    call.set_code(code.value());
-  call.perform();
+void AlarmControlPanel::arm_custom_bypass(const char *code) {
+  this->arm_with_code_(&AlarmControlPanelCall::arm_custom_bypass, code);
 }
 
-void AlarmControlPanel::arm_vacation(optional<std::string> code) {
-  auto call = this->make_call();
-  call.arm_vacation();
-  if (code.has_value())
-    call.set_code(code.value());
-  call.perform();
-}
-
-void AlarmControlPanel::arm_custom_bypass(optional<std::string> code) {
-  auto call = this->make_call();
-  call.arm_custom_bypass();
-  if (code.has_value())
-    call.set_code(code.value());
-  call.perform();
-}
-
-void AlarmControlPanel::disarm(optional<std::string> code) {
-  auto call = this->make_call();
-  call.disarm();
-  if (code.has_value())
-    call.set_code(code.value());
-  call.perform();
-}
+void AlarmControlPanel::disarm(const char *code) { this->arm_with_code_(&AlarmControlPanelCall::disarm, code); }
 
 }  // namespace esphome::alarm_control_panel
diff --git a/esphome/components/alarm_control_panel/alarm_control_panel.h b/esphome/components/alarm_control_panel/alarm_control_panel.h
index 340f15bcd6..e8dc197e26 100644
--- a/esphome/components/alarm_control_panel/alarm_control_panel.h
+++ b/esphome/components/alarm_control_panel/alarm_control_panel.h
@@ -76,37 +76,53 @@ class AlarmControlPanel : public EntityBase {
    *
    * @param code The code
    */
-  void arm_away(optional<std::string> code = nullopt);
+  void arm_away(const char *code = nullptr);
+  void arm_away(const optional<std::string> &code) {
+    this->arm_away(code.has_value() ? code.value().c_str() : nullptr);
+  }
 
   /** arm the alarm in home mode
    *
    * @param code The code
    */
-  void arm_home(optional<std::string> code = nullopt);
+  void arm_home(const char *code = nullptr);
+  void arm_home(const optional<std::string> &code) {
+    this->arm_home(code.has_value() ? code.value().c_str() : nullptr);
+  }
 
   /** arm the alarm in night mode
    *
    * @param code The code
    */
-  void arm_night(optional<std::string> code = nullopt);
+  void arm_night(const char *code = nullptr);
+  void arm_night(const optional<std::string> &code) {
+    this->arm_night(code.has_value() ? code.value().c_str() : nullptr);
+  }
 
   /** arm the alarm in vacation mode
    *
    * @param code The code
    */
-  void arm_vacation(optional<std::string> code = nullopt);
+  void arm_vacation(const char *code = nullptr);
+  void arm_vacation(const optional<std::string> &code) {
+    this->arm_vacation(code.has_value() ? code.value().c_str() : nullptr);
+  }
 
   /** arm the alarm in custom bypass mode
    *
    * @param code The code
    */
-  void arm_custom_bypass(optional<std::string> code = nullopt);
+  void arm_custom_bypass(const char *code = nullptr);
+  void arm_custom_bypass(const optional<std::string> &code) {
+    this->arm_custom_bypass(code.has_value() ? code.value().c_str() : nullptr);
+  }
 
   /** disarm the alarm
    *
    * @param code The code
    */
-  void disarm(optional<std::string> code = nullopt);
+  void disarm(const char *code = nullptr);
+  void disarm(const optional<std::string> &code) { this->disarm(code.has_value() ? code.value().c_str() : nullptr); }
 
   /** Get the state
    *
@@ -118,6 +134,8 @@ class AlarmControlPanel : public EntityBase {
 
  protected:
   friend AlarmControlPanelCall;
+  // Helper to reduce code duplication for arm/disarm methods
+  void arm_with_code_(AlarmControlPanelCall &(AlarmControlPanelCall::*arm_method)(), const char *code);
   // in order to store last panel state in flash
   ESPPreferenceObject pref_;
   // current state
diff --git a/esphome/components/alarm_control_panel/alarm_control_panel_call.cpp b/esphome/components/alarm_control_panel/alarm_control_panel_call.cpp
index 5e98d58368..ba58ee3904 100644
--- a/esphome/components/alarm_control_panel/alarm_control_panel_call.cpp
+++ b/esphome/components/alarm_control_panel/alarm_control_panel_call.cpp
@@ -10,8 +10,10 @@ static const char *const TAG = "alarm_control_panel";
 
 AlarmControlPanelCall::AlarmControlPanelCall(AlarmControlPanel *parent) : parent_(parent) {}
 
-AlarmControlPanelCall &AlarmControlPanelCall::set_code(const std::string &code) {
-  this->code_ = code;
+AlarmControlPanelCall &AlarmControlPanelCall::set_code(const char *code) {
+  if (code != nullptr) {
+    this->code_ = std::string(code);
+  }
   return *this;
 }
 
diff --git a/esphome/components/alarm_control_panel/alarm_control_panel_call.h b/esphome/components/alarm_control_panel/alarm_control_panel_call.h
index cff00900dd..58764ea166 100644
--- a/esphome/components/alarm_control_panel/alarm_control_panel_call.h
+++ b/esphome/components/alarm_control_panel/alarm_control_panel_call.h
@@ -14,7 +14,8 @@ class AlarmControlPanelCall {
  public:
   AlarmControlPanelCall(AlarmControlPanel *parent);
 
-  AlarmControlPanelCall &set_code(const std::string &code);
+  AlarmControlPanelCall &set_code(const char *code);
+  AlarmControlPanelCall &set_code(const std::string &code) { return this->set_code(code.c_str()); }
   AlarmControlPanelCall &arm_away();
   AlarmControlPanelCall &arm_home();
   AlarmControlPanelCall &arm_night();
diff --git a/esphome/components/alarm_control_panel/automation.h b/esphome/components/alarm_control_panel/automation.h
index ce5ceadb47..4ff34de0d5 100644
--- a/esphome/components/alarm_control_panel/automation.h
+++ b/esphome/components/alarm_control_panel/automation.h
@@ -66,15 +66,7 @@ template<typename... Ts> class ArmAwayAction : public Action<Ts...> {
 
   TEMPLATABLE_VALUE(std::string, code)
 
-  void play(const Ts &...x) override {
-    auto call = this->alarm_control_panel_->make_call();
-    auto code = this->code_.optional_value(x...);
-    if (code.has_value()) {
-      call.set_code(code.value());
-    }
-    call.arm_away();
-    call.perform();
-  }
+  void play(const Ts &...x) override { this->alarm_control_panel_->arm_away(this->code_.optional_value(x...)); }
 
  protected:
   AlarmControlPanel *alarm_control_panel_;
@@ -86,15 +78,7 @@ template<typename... Ts> class ArmHomeAction : public Action<Ts...> {
 
   TEMPLATABLE_VALUE(std::string, code)
 
-  void play(const Ts &...x) override {
-    auto call = this->alarm_control_panel_->make_call();
-    auto code = this->code_.optional_value(x...);
-    if (code.has_value()) {
-      call.set_code(code.value());
-    }
-    call.arm_home();
-    call.perform();
-  }
+  void play(const Ts &...x) override { this->alarm_control_panel_->arm_home(this->code_.optional_value(x...)); }
 
  protected:
   AlarmControlPanel *alarm_control_panel_;
@@ -106,15 +90,7 @@ template<typename... Ts> class ArmNightAction : public Action<Ts...> {
 
   TEMPLATABLE_VALUE(std::string, code)
 
-  void play(const Ts &...x) override {
-    auto call = this->alarm_control_panel_->make_call();
-    auto code = this->code_.optional_value(x...);
-    if (code.has_value()) {
-      call.set_code(code.value());
-    }
-    call.arm_night();
-    call.perform();
-  }
+  void play(const Ts &...x) override { this->alarm_control_panel_->arm_night(this->code_.optional_value(x...)); }
 
  protected:
   AlarmControlPanel *alarm_control_panel_;
diff --git a/esphome/components/am43/am43_base.cpp b/esphome/components/am43/am43_base.cpp
index af474dcb79..d70e638382 100644
--- a/esphome/components/am43/am43_base.cpp
+++ b/esphome/components/am43/am43_base.cpp
@@ -1,21 +1,12 @@
 #include "am43_base.h"
+#include "esphome/core/helpers.h"
 #include <cstring>
-#include <cstdio>
 
 namespace esphome {
 namespace am43 {
 
 const uint8_t START_PACKET[5] = {0x00, 0xff, 0x00, 0x00, 0x9a};
 
-std::string pkt_to_hex(const uint8_t *data, uint16_t len) {
-  char buf[64];
-  memset(buf, 0, 64);
-  for (int i = 0; i < len; i++)
-    sprintf(&buf[i * 2], "%02x", data[i]);
-  std::string ret = buf;
-  return ret;
-}
-
 Am43Packet *Am43Encoder::get_battery_level_request() {
   uint8_t data = 0x1;
   return this->encode_(0xA2, &data, 1);
@@ -73,7 +64,9 @@ Am43Packet *Am43Encoder::encode_(uint8_t command, uint8_t *data, uint8_t length)
   memcpy(&this->packet_.data[7], data, length);
   this->packet_.length = length + 7;
   this->checksum_();
-  ESP_LOGV("am43", "ENC(%d): 0x%s", packet_.length, pkt_to_hex(packet_.data, packet_.length).c_str());
+  char hex_buf[format_hex_size(sizeof(this->packet_.data))];
+  ESP_LOGV("am43", "ENC(%d): 0x%s", this->packet_.length,
+           format_hex_to(hex_buf, this->packet_.data, this->packet_.length));
   return &this->packet_;
 }
 
@@ -88,7 +81,8 @@ void Am43Decoder::decode(const uint8_t *data, uint16_t length) {
   this->has_set_state_response_ = false;
   this->has_position_ = false;
   this->has_pin_response_ = false;
-  ESP_LOGV("am43", "DEC(%d): 0x%s", length, pkt_to_hex(data, length).c_str());
+  char hex_buf[format_hex_size(24)];  // Max expected packet size
+  ESP_LOGV("am43", "DEC(%d): 0x%s", length, format_hex_to(hex_buf, data, length));
 
   if (length < 2 || data[0] != 0x9a)
     return;
diff --git a/esphome/components/anova/anova_base.cpp b/esphome/components/anova/anova_base.cpp
index ce4febbe37..fef4f1d852 100644
--- a/esphome/components/anova/anova_base.cpp
+++ b/esphome/components/anova/anova_base.cpp
@@ -18,31 +18,31 @@ AnovaPacket *AnovaCodec::clean_packet_() {
 
 AnovaPacket *AnovaCodec::get_read_device_status_request() {
   this->current_query_ = READ_DEVICE_STATUS;
-  sprintf((char *) this->packet_.data, "%s", CMD_READ_DEVICE_STATUS);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_READ_DEVICE_STATUS);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_read_target_temp_request() {
   this->current_query_ = READ_TARGET_TEMPERATURE;
-  sprintf((char *) this->packet_.data, "%s", CMD_READ_TARGET_TEMP);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_READ_TARGET_TEMP);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_read_current_temp_request() {
   this->current_query_ = READ_CURRENT_TEMPERATURE;
-  sprintf((char *) this->packet_.data, "%s", CMD_READ_CURRENT_TEMP);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_READ_CURRENT_TEMP);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_read_unit_request() {
   this->current_query_ = READ_UNIT;
-  sprintf((char *) this->packet_.data, "%s", CMD_READ_UNIT);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_READ_UNIT);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_read_data_request() {
   this->current_query_ = READ_DATA;
-  sprintf((char *) this->packet_.data, "%s", CMD_READ_DATA);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_READ_DATA);
   return this->clean_packet_();
 }
 
@@ -50,25 +50,25 @@ AnovaPacket *AnovaCodec::get_set_target_temp_request(float temperature) {
   this->current_query_ = SET_TARGET_TEMPERATURE;
   if (this->fahrenheit_)
     temperature = ctof(temperature);
-  sprintf((char *) this->packet_.data, CMD_SET_TARGET_TEMP, temperature);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), CMD_SET_TARGET_TEMP, temperature);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_set_unit_request(char unit) {
   this->current_query_ = SET_UNIT;
-  sprintf((char *) this->packet_.data, CMD_SET_TEMP_UNIT, unit);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), CMD_SET_TEMP_UNIT, unit);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_start_request() {
   this->current_query_ = START;
-  sprintf((char *) this->packet_.data, CMD_START);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_START);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_stop_request() {
   this->current_query_ = STOP;
-  sprintf((char *) this->packet_.data, CMD_STOP);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_STOP);
   return this->clean_packet_();
 }
 
diff --git a/esphome/components/api/api_connection.cpp b/esphome/components/api/api_connection.cpp
index 0804985cc5..0364879ccd 100644
--- a/esphome/components/api/api_connection.cpp
+++ b/esphome/components/api/api_connection.cpp
@@ -1712,17 +1712,16 @@ void APIConnection::on_home_assistant_state_response(const HomeAssistantStateRes
     }
 
     // Create null-terminated state for callback (parse_number needs null-termination)
-    // HA state max length is 255, so 256 byte buffer covers all cases
-    char state_buf[256];
-    size_t copy_len = msg.state.size();
-    if (copy_len >= sizeof(state_buf)) {
-      copy_len = sizeof(state_buf) - 1;  // Truncate to leave space for null terminator
+    // HA state max length is 255 characters, but attributes can be much longer
+    // Use stack buffer for common case (states), heap fallback for large attributes
+    size_t state_len = msg.state.size();
+    SmallBufferWithHeapFallback<MAX_STATE_LEN + 1> state_buf_alloc(state_len + 1);
+    char *state_buf = reinterpret_cast<char *>(state_buf_alloc.get());
+    if (state_len > 0) {
+      memcpy(state_buf, msg.state.c_str(), state_len);
     }
-    if (copy_len > 0) {
-      memcpy(state_buf, msg.state.c_str(), copy_len);
-    }
-    state_buf[copy_len] = '\0';
-    it.callback(StringRef(state_buf, copy_len));
+    state_buf[state_len] = '\0';
+    it.callback(StringRef(state_buf, state_len));
   }
 }
 #endif
diff --git a/esphome/components/api/api_frame_helper_noise.cpp b/esphome/components/api/api_frame_helper_noise.cpp
index 21b0463dfe..4a9257231d 100644
--- a/esphome/components/api/api_frame_helper_noise.cpp
+++ b/esphome/components/api/api_frame_helper_noise.cpp
@@ -3,6 +3,7 @@
 #ifdef USE_API_NOISE
 #include "api_connection.h"  // For ClientInfo struct
 #include "esphome/core/application.h"
+#include "esphome/core/entity_base.h"
 #include "esphome/core/hal.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
@@ -256,28 +257,30 @@ APIError APINoiseFrameHelper::state_action_() {
   }
   if (state_ == State::SERVER_HELLO) {
     // send server hello
-    constexpr size_t mac_len = 13;  // 12 hex chars + null terminator
     const std::string &name = App.get_name();
-    char mac[mac_len];
+    char mac[MAC_ADDRESS_BUFFER_SIZE];
     get_mac_address_into_buffer(mac);
 
     // Calculate positions and sizes
     size_t name_len = name.size() + 1;  // including null terminator
     size_t name_offset = 1;
     size_t mac_offset = name_offset + name_len;
-    size_t total_size = 1 + name_len + mac_len;
+    size_t total_size = 1 + name_len + MAC_ADDRESS_BUFFER_SIZE;
 
-    auto msg = std::make_unique<uint8_t[]>(total_size);
+    // 1 (proto) + name (max ESPHOME_DEVICE_NAME_MAX_LEN) + 1 (name null)
+    // + mac (MAC_ADDRESS_BUFFER_SIZE - 1) + 1 (mac null)
+    constexpr size_t max_msg_size = 1 + ESPHOME_DEVICE_NAME_MAX_LEN + 1 + MAC_ADDRESS_BUFFER_SIZE;
+    uint8_t msg[max_msg_size];
 
     // chosen proto
     msg[0] = 0x01;
 
     // node name, terminated by null byte
-    std::memcpy(msg.get() + name_offset, name.c_str(), name_len);
+    std::memcpy(msg + name_offset, name.c_str(), name_len);
     // node mac, terminated by null byte
-    std::memcpy(msg.get() + mac_offset, mac, mac_len);
+    std::memcpy(msg + mac_offset, mac, MAC_ADDRESS_BUFFER_SIZE);
 
-    aerr = write_frame_(msg.get(), total_size);
+    aerr = write_frame_(msg, total_size);
     if (aerr != APIError::OK)
       return aerr;
 
@@ -353,35 +356,32 @@ APIError APINoiseFrameHelper::state_action_() {
   return APIError::OK;
 }
 void APINoiseFrameHelper::send_explicit_handshake_reject_(const LogString *reason) {
+  // Max reject message: "Bad handshake packet len" (24) + 1 (failure byte) = 25 bytes
+  uint8_t data[32];
+  data[0] = 0x01;  // failure
+
 #ifdef USE_STORE_LOG_STR_IN_FLASH
   // On ESP8266 with flash strings, we need to use PROGMEM-aware functions
   size_t reason_len = strlen_P(reinterpret_cast<PGM_P>(reason));
-  size_t data_size = reason_len + 1;
-  auto data = std::make_unique<uint8_t[]>(data_size);
-  data[0] = 0x01;  // failure
-
-  // Copy error message from PROGMEM
   if (reason_len > 0) {
-    memcpy_P(data.get() + 1, reinterpret_cast<PGM_P>(reason), reason_len);
+    memcpy_P(data + 1, reinterpret_cast<PGM_P>(reason), reason_len);
   }
 #else
   // Normal memory access
   const char *reason_str = LOG_STR_ARG(reason);
   size_t reason_len = strlen(reason_str);
-  size_t data_size = reason_len + 1;
-  auto data = std::make_unique<uint8_t[]>(data_size);
-  data[0] = 0x01;  // failure
-
-  // Copy error message in bulk
   if (reason_len > 0) {
-    std::memcpy(data.get() + 1, reason_str, reason_len);
+    // NOLINTNEXTLINE(bugprone-not-null-terminated-result) - binary protocol, not a C string
+    std::memcpy(data + 1, reason_str, reason_len);
   }
 #endif
 
+  size_t data_size = reason_len + 1;
+
   // temporarily remove failed state
   auto orig_state = state_;
   state_ = State::EXPLICIT_REJECT;
-  write_frame_(data.get(), data_size);
+  write_frame_(data, data_size);
   state_ = orig_state;
 }
 APIError APINoiseFrameHelper::read_packet(ReadPacketBuffer *buffer) {
diff --git a/esphome/components/api/proto.cpp b/esphome/components/api/proto.cpp
index eac26997cf..2a0ddf91db 100644
--- a/esphome/components/api/proto.cpp
+++ b/esphome/components/api/proto.cpp
@@ -48,14 +48,14 @@ uint32_t ProtoDecodableMessage::count_repeated_field(const uint8_t *buffer, size
         }
         uint32_t field_length = res->as_uint32();
         ptr += consumed;
-        if (ptr + field_length > end) {
+        if (field_length > static_cast<size_t>(end - ptr)) {
           return count;  // Out of bounds
         }
         ptr += field_length;
         break;
       }
       case WIRE_TYPE_FIXED32: {  // 32-bit - skip 4 bytes
-        if (ptr + 4 > end) {
+        if (end - ptr < 4) {
           return count;
         }
         ptr += 4;
@@ -110,7 +110,7 @@ void ProtoDecodableMessage::decode(const uint8_t *buffer, size_t length) {
         }
         uint32_t field_length = res->as_uint32();
         ptr += consumed;
-        if (ptr + field_length > end) {
+        if (field_length > static_cast<size_t>(end - ptr)) {
           ESP_LOGV(TAG, "Out-of-bounds Length Delimited at offset %ld", (long) (ptr - buffer));
           return;
         }
@@ -121,7 +121,7 @@ void ProtoDecodableMessage::decode(const uint8_t *buffer, size_t length) {
         break;
       }
       case WIRE_TYPE_FIXED32: {  // 32-bit
-        if (ptr + 4 > end) {
+        if (end - ptr < 4) {
           ESP_LOGV(TAG, "Out-of-bounds Fixed32-bit at offset %ld", (long) (ptr - buffer));
           return;
         }
diff --git a/esphome/components/atm90e32/atm90e32.cpp b/esphome/components/atm90e32/atm90e32.cpp
index 634260b5e9..f4c199cb98 100644
--- a/esphome/components/atm90e32/atm90e32.cpp
+++ b/esphome/components/atm90e32/atm90e32.cpp
@@ -158,12 +158,14 @@ void ATM90E32Component::setup() {
 
   if (this->enable_offset_calibration_) {
     // Initialize flash storage for offset calibrations
-    uint32_t o_hash = fnv1_hash(std::string("_offset_calibration_") + this->cs_summary_);
+    uint32_t o_hash = fnv1_hash("_offset_calibration_");
+    o_hash = fnv1_hash_extend(o_hash, this->cs_summary_);
     this->offset_pref_ = global_preferences->make_preference<OffsetCalibration[3]>(o_hash, true);
     this->restore_offset_calibrations_();
 
     // Initialize flash storage for power offset calibrations
-    uint32_t po_hash = fnv1_hash(std::string("_power_offset_calibration_") + this->cs_summary_);
+    uint32_t po_hash = fnv1_hash("_power_offset_calibration_");
+    po_hash = fnv1_hash_extend(po_hash, this->cs_summary_);
     this->power_offset_pref_ = global_preferences->make_preference<PowerOffsetCalibration[3]>(po_hash, true);
     this->restore_power_offset_calibrations_();
   } else {
@@ -183,7 +185,8 @@ void ATM90E32Component::setup() {
 
   if (this->enable_gain_calibration_) {
     // Initialize flash storage for gain calibration
-    uint32_t g_hash = fnv1_hash(std::string("_gain_calibration_") + this->cs_summary_);
+    uint32_t g_hash = fnv1_hash("_gain_calibration_");
+    g_hash = fnv1_hash_extend(g_hash, this->cs_summary_);
     this->gain_calibration_pref_ = global_preferences->make_preference<GainCalibration[3]>(g_hash, true);
     this->restore_gain_calibrations_();
 
diff --git a/esphome/components/audio/__init__.py b/esphome/components/audio/__init__.py
index 7b03e4b6a7..6c721652e1 100644
--- a/esphome/components/audio/__init__.py
+++ b/esphome/components/audio/__init__.py
@@ -1,4 +1,5 @@
 import esphome.codegen as cg
+from esphome.components.esp32 import add_idf_component
 import esphome.config_validation as cv
 from esphome.const import CONF_BITS_PER_SAMPLE, CONF_NUM_CHANNELS, CONF_SAMPLE_RATE
 import esphome.final_validate as fv
@@ -165,4 +166,7 @@ def final_validate_audio_schema(
 
 
 async def to_code(config):
-    cg.add_library("esphome/esp-audio-libs", "2.0.1")
+    add_idf_component(
+        name="esphome/esp-audio-libs",
+        ref="2.0.3",
+    )
diff --git a/esphome/components/audio/audio_decoder.cpp b/esphome/components/audio/audio_decoder.cpp
index d1ad571a52..8f514468c4 100644
--- a/esphome/components/audio/audio_decoder.cpp
+++ b/esphome/components/audio/audio_decoder.cpp
@@ -300,7 +300,7 @@ FileDecoderState AudioDecoder::decode_mp3_() {
 
   // Advance read pointer to match the offset for the syncword
   this->input_transfer_buffer_->decrease_buffer_length(offset);
-  uint8_t *buffer_start = this->input_transfer_buffer_->get_buffer_start();
+  const uint8_t *buffer_start = this->input_transfer_buffer_->get_buffer_start();
 
   buffer_length = (int) this->input_transfer_buffer_->available();
   int err = esp_audio_libs::helix_decoder::MP3Decode(this->mp3_decoder_, &buffer_start, &buffer_length,
diff --git a/esphome/components/audio/audio_reader.cpp b/esphome/components/audio/audio_reader.cpp
index 7794187a69..4e4bd31f9b 100644
--- a/esphome/components/audio/audio_reader.cpp
+++ b/esphome/components/audio/audio_reader.cpp
@@ -185,18 +185,16 @@ esp_err_t AudioReader::start(const std::string &uri, AudioFileType &file_type) {
       return err;
     }
 
-    std::string url_string = str_lower_case(url);
-
-    if (str_endswith(url_string, ".wav")) {
+    if (str_endswith_ignore_case(url, ".wav")) {
       file_type = AudioFileType::WAV;
     }
 #ifdef USE_AUDIO_MP3_SUPPORT
-    else if (str_endswith(url_string, ".mp3")) {
+    else if (str_endswith_ignore_case(url, ".mp3")) {
       file_type = AudioFileType::MP3;
     }
 #endif
 #ifdef USE_AUDIO_FLAC_SUPPORT
-    else if (str_endswith(url_string, ".flac")) {
+    else if (str_endswith_ignore_case(url, ".flac")) {
       file_type = AudioFileType::FLAC;
     }
 #endif
diff --git a/esphome/components/bluetooth_proxy/bluetooth_connection.cpp b/esphome/components/bluetooth_proxy/bluetooth_connection.cpp
index 1d6f7e23b3..60f56fda54 100644
--- a/esphome/components/bluetooth_proxy/bluetooth_connection.cpp
+++ b/esphome/components/bluetooth_proxy/bluetooth_connection.cpp
@@ -135,8 +135,8 @@ void BluetoothConnection::loop() {
   // - For V3_WITH_CACHE: Services are never sent, disable after INIT state
   // - For V3_WITHOUT_CACHE: Disable only after service discovery is complete
   //   (send_service_ == DONE_SENDING_SERVICES, which is only set after services are sent)
-  if (this->state_ != espbt::ClientState::INIT && (this->connection_type_ == espbt::ConnectionType::V3_WITH_CACHE ||
-                                                   this->send_service_ == DONE_SENDING_SERVICES)) {
+  if (this->state() != espbt::ClientState::INIT && (this->connection_type_ == espbt::ConnectionType::V3_WITH_CACHE ||
+                                                    this->send_service_ == DONE_SENDING_SERVICES)) {
     this->disable_loop();
   }
 }
diff --git a/esphome/components/cc1101/cc1101.cpp b/esphome/components/cc1101/cc1101.cpp
index c4507a54e5..46cd89e0e8 100644
--- a/esphome/components/cc1101/cc1101.cpp
+++ b/esphome/components/cc1101/cc1101.cpp
@@ -152,6 +152,13 @@ void CC1101Component::setup() {
   }
 }
 
+void CC1101Component::call_listeners_(const std::vector<uint8_t> &packet, float freq_offset, float rssi, uint8_t lqi) {
+  for (auto &listener : this->listeners_) {
+    listener->on_packet(packet, freq_offset, rssi, lqi);
+  }
+  this->packet_trigger_->trigger(packet, freq_offset, rssi, lqi);
+}
+
 void CC1101Component::loop() {
   if (this->state_.PKT_FORMAT != static_cast<uint8_t>(PacketFormat::PACKET_FORMAT_FIFO) || this->gdo0_pin_ == nullptr ||
       !this->gdo0_pin_->digital_read()) {
@@ -198,7 +205,7 @@ void CC1101Component::loop() {
   bool crc_ok = (this->state_.LQI & STATUS_CRC_OK_MASK) != 0;
   uint8_t lqi = this->state_.LQI & STATUS_LQI_MASK;
   if (this->state_.CRC_EN == 0 || crc_ok) {
-    this->packet_trigger_->trigger(this->packet_, freq_offset, rssi, lqi);
+    this->call_listeners_(this->packet_, freq_offset, rssi, lqi);
   }
 
   // Return to rx
diff --git a/esphome/components/cc1101/cc1101.h b/esphome/components/cc1101/cc1101.h
index 43ae5b3612..6e3f01af90 100644
--- a/esphome/components/cc1101/cc1101.h
+++ b/esphome/components/cc1101/cc1101.h
@@ -11,6 +11,11 @@ namespace esphome::cc1101 {
 
 enum class CC1101Error { NONE = 0, TIMEOUT, PARAMS, CRC_ERROR, FIFO_OVERFLOW, PLL_LOCK };
 
+class CC1101Listener {
+ public:
+  virtual void on_packet(const std::vector<uint8_t> &packet, float freq_offset, float rssi, uint8_t lqi) = 0;
+};
+
 class CC1101Component : public Component,
                         public spi::SPIDevice<spi::BIT_ORDER_MSB_FIRST, spi::CLOCK_POLARITY_LOW,
                                               spi::CLOCK_PHASE_LEADING, spi::DATA_RATE_1MHZ> {
@@ -73,6 +78,7 @@ class CC1101Component : public Component,
 
   // Packet mode operations
   CC1101Error transmit_packet(const std::vector<uint8_t> &packet);
+  void register_listener(CC1101Listener *listener) { this->listeners_.push_back(listener); }
   Trigger<std::vector<uint8_t>, float, float, uint8_t> *get_packet_trigger() const { return this->packet_trigger_; }
 
  protected:
@@ -89,9 +95,11 @@ class CC1101Component : public Component,
   InternalGPIOPin *gdo0_pin_{nullptr};
 
   // Packet handling
+  void call_listeners_(const std::vector<uint8_t> &packet, float freq_offset, float rssi, uint8_t lqi);
   Trigger<std::vector<uint8_t>, float, float, uint8_t> *packet_trigger_{
       new Trigger<std::vector<uint8_t>, float, float, uint8_t>()};
   std::vector<uint8_t> packet_;
+  std::vector<CC1101Listener *> listeners_;
 
   // Low-level Helpers
   uint8_t strobe_(Command cmd);
diff --git a/esphome/components/ccs811/ccs811.cpp b/esphome/components/ccs811/ccs811.cpp
index 84355f2793..9ff01b32b2 100644
--- a/esphome/components/ccs811/ccs811.cpp
+++ b/esphome/components/ccs811/ccs811.cpp
@@ -81,8 +81,8 @@ void CCS811Component::setup() {
            bootloader_version, application_version);
   if (this->version_ != nullptr) {
     char version[20];  // "15.15.15 (0xffff)" is 17 chars, plus NUL, plus wiggle room
-    sprintf(version, "%d.%d.%d (0x%02x)", (application_version >> 12 & 15), (application_version >> 8 & 15),
-            (application_version >> 4 & 15), application_version);
+    buf_append_printf(version, sizeof(version), 0, "%d.%d.%d (0x%02x)", (application_version >> 12 & 15),
+                      (application_version >> 8 & 15), (application_version >> 4 & 15), application_version);
     ESP_LOGD(TAG, "publishing version state: %s", version);
     this->version_->publish_state(version);
   }
diff --git a/esphome/components/ch422g/ch422g.cpp b/esphome/components/ch422g/ch422g.cpp
index d031c31294..eef95b9ba2 100644
--- a/esphome/components/ch422g/ch422g.cpp
+++ b/esphome/components/ch422g/ch422g.cpp
@@ -133,7 +133,7 @@ bool CH422GGPIOPin::digital_read() { return this->parent_->digital_read(this->pi
 
 void CH422GGPIOPin::digital_write(bool value) { this->parent_->digital_write(this->pin_, value ^ this->inverted_); }
 size_t CH422GGPIOPin::dump_summary(char *buffer, size_t len) const {
-  return snprintf(buffer, len, "EXIO%u via CH422G", this->pin_);
+  return buf_append_printf(buffer, len, 0, "EXIO%u via CH422G", this->pin_);
 }
 void CH422GGPIOPin::set_flags(gpio::Flags flags) {
   flags_ = flags;
diff --git a/esphome/components/cs5460a/cs5460a.h b/esphome/components/cs5460a/cs5460a.h
index 11b13f5851..99c3017510 100644
--- a/esphome/components/cs5460a/cs5460a.h
+++ b/esphome/components/cs5460a/cs5460a.h
@@ -76,7 +76,6 @@ class CS5460AComponent : public Component,
   void restart() { restart_(); }
 
   void setup() override;
-  void loop() override {}
   void dump_config() override;
 
  protected:
diff --git a/esphome/components/cse7766/cse7766.cpp b/esphome/components/cse7766/cse7766.cpp
index 71fe15f0ae..4432195365 100644
--- a/esphome/components/cse7766/cse7766.cpp
+++ b/esphome/components/cse7766/cse7766.cpp
@@ -207,20 +207,24 @@ void CSE7766Component::parse_data_() {
 
 #if ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_VERY_VERBOSE
   {
-    std::string buf = "Parsed:";
+    // Buffer: 7 + 15 + 33 + 15 + 25 = 95 chars max + null, rounded to 128 for safety margin.
+    // Float sizes with %.4f can be up to 11 chars for large values (e.g., 999999.9999).
+    char buf[128];
+    size_t pos = buf_append_printf(buf, sizeof(buf), 0, "Parsed:");
     if (have_voltage) {
-      buf += str_sprintf(" V=%fV", voltage);
+      pos = buf_append_printf(buf, sizeof(buf), pos, " V=%.4fV", voltage);
     }
     if (have_current) {
-      buf += str_sprintf(" I=%fmA (~%fmA)", current * 1000.0f, calculated_current * 1000.0f);
+      pos = buf_append_printf(buf, sizeof(buf), pos, " I=%.4fmA (~%.4fmA)", current * 1000.0f,
+                              calculated_current * 1000.0f);
     }
     if (have_power) {
-      buf += str_sprintf(" P=%fW", power);
+      pos = buf_append_printf(buf, sizeof(buf), pos, " P=%.4fW", power);
     }
     if (energy != 0.0f) {
-      buf += str_sprintf(" E=%fkWh (%u)", energy, cf_pulses);
+      buf_append_printf(buf, sizeof(buf), pos, " E=%.4fkWh (%u)", energy, cf_pulses);
     }
-    ESP_LOGVV(TAG, "%s", buf.c_str());
+    ESP_LOGVV(TAG, "%s", buf);
   }
 #endif
 }
diff --git a/esphome/components/daikin_arc/daikin_arc.cpp b/esphome/components/daikin_arc/daikin_arc.cpp
index f05342f482..4726310806 100644
--- a/esphome/components/daikin_arc/daikin_arc.cpp
+++ b/esphome/components/daikin_arc/daikin_arc.cpp
@@ -258,8 +258,9 @@ bool DaikinArcClimate::parse_state_frame_(const uint8_t frame[]) {
   }
 
   char buf[DAIKIN_STATE_FRAME_SIZE * 3 + 1] = {0};
+  size_t pos = 0;
   for (size_t i = 0; i < DAIKIN_STATE_FRAME_SIZE; i++) {
-    sprintf(buf, "%s%02x ", buf, frame[i]);
+    pos = buf_append_printf(buf, sizeof(buf), pos, "%02x ", frame[i]);
   }
   ESP_LOGD(TAG, "FRAME %s", buf);
 
@@ -349,8 +350,9 @@ bool DaikinArcClimate::on_receive(remote_base::RemoteReceiveData data) {
   if (data.expect_item(DAIKIN_HEADER_MARK, DAIKIN_HEADER_SPACE)) {
     valid_daikin_frame = true;
     size_t bytes_count = data.size() / 2 / 8;
-    std::unique_ptr<char[]> buf(new char[bytes_count * 3 + 1]);
-    buf[0] = '\0';
+    size_t buf_size = bytes_count * 3 + 1;
+    std::unique_ptr<char[]> buf(new char[buf_size]());  // value-initialize (zero-fill)
+    size_t buf_pos = 0;
     for (size_t i = 0; i < bytes_count; i++) {
       uint8_t byte = 0;
       for (int8_t bit = 0; bit < 8; bit++) {
@@ -361,19 +363,19 @@ bool DaikinArcClimate::on_receive(remote_base::RemoteReceiveData data) {
           break;
         }
       }
-      sprintf(buf.get(), "%s%02x ", buf.get(), byte);
+      buf_pos = buf_append_printf(buf.get(), buf_size, buf_pos, "%02x ", byte);
     }
     ESP_LOGD(TAG, "WHOLE FRAME %s  size: %d", buf.get(), data.size());
   }
   if (!valid_daikin_frame) {
-    char sbuf[16 * 10 + 1];
-    sbuf[0] = '\0';
+    char sbuf[16 * 10 + 1] = {0};
+    size_t sbuf_pos = 0;
     for (size_t j = 0; j < static_cast<size_t>(data.size()); j++) {
       if ((j - 2) % 16 == 0) {
         if (j > 0) {
           ESP_LOGD(TAG, "DATA %04x: %s", (j - 16 > 0xffff ? 0 : j - 16), sbuf);
         }
-        sbuf[0] = '\0';
+        sbuf_pos = 0;
       }
       char type_ch = ' ';
       // debug_tolerance = 25%
@@ -401,9 +403,10 @@ bool DaikinArcClimate::on_receive(remote_base::RemoteReceiveData data) {
         type_ch = '0';
 
       if (abs(data[j]) > 100000) {
-        sprintf(sbuf, "%s%-5d[%c] ", sbuf, data[j] > 0 ? 99999 : -99999, type_ch);
+        sbuf_pos = buf_append_printf(sbuf, sizeof(sbuf), sbuf_pos, "%-5d[%c] ", data[j] > 0 ? 99999 : -99999, type_ch);
       } else {
-        sprintf(sbuf, "%s%-5d[%c] ", sbuf, (int) (round(data[j] / 10.) * 10), type_ch);
+        sbuf_pos =
+            buf_append_printf(sbuf, sizeof(sbuf), sbuf_pos, "%-5d[%c] ", (int) (round(data[j] / 10.) * 10), type_ch);
       }
       if (j + 1 == static_cast<size_t>(data.size())) {
         ESP_LOGD(TAG, "DATA %04x: %s", (j - 8 > 0xffff ? 0 : j - 8), sbuf);
diff --git a/esphome/components/datetime/date_entity.cpp b/esphome/components/datetime/date_entity.cpp
index c5ea051914..3ba488c0aa 100644
--- a/esphome/components/datetime/date_entity.cpp
+++ b/esphome/components/datetime/date_entity.cpp
@@ -106,9 +106,9 @@ DateCall &DateCall::set_date(uint16_t year, uint8_t month, uint8_t day) {
 
 DateCall &DateCall::set_date(ESPTime time) { return this->set_date(time.year, time.month, time.day_of_month); };
 
-DateCall &DateCall::set_date(const std::string &date) {
+DateCall &DateCall::set_date(const char *date, size_t len) {
   ESPTime val{};
-  if (!ESPTime::strptime(date, val)) {
+  if (!ESPTime::strptime(date, len, val)) {
     ESP_LOGE(TAG, "Could not convert the date string to an ESPTime object");
     return *this;
   }
diff --git a/esphome/components/datetime/date_entity.h b/esphome/components/datetime/date_entity.h
index 069116d162..955fd92c45 100644
--- a/esphome/components/datetime/date_entity.h
+++ b/esphome/components/datetime/date_entity.h
@@ -67,7 +67,9 @@ class DateCall {
   void perform();
   DateCall &set_date(uint16_t year, uint8_t month, uint8_t day);
   DateCall &set_date(ESPTime time);
-  DateCall &set_date(const std::string &date);
+  DateCall &set_date(const char *date, size_t len);
+  DateCall &set_date(const char *date) { return this->set_date(date, strlen(date)); }
+  DateCall &set_date(const std::string &date) { return this->set_date(date.c_str(), date.size()); }
 
   DateCall &set_year(uint16_t year) {
     this->year_ = year;
diff --git a/esphome/components/datetime/datetime_entity.cpp b/esphome/components/datetime/datetime_entity.cpp
index fd3901fcfc..730abb3ca8 100644
--- a/esphome/components/datetime/datetime_entity.cpp
+++ b/esphome/components/datetime/datetime_entity.cpp
@@ -163,9 +163,9 @@ DateTimeCall &DateTimeCall::set_datetime(ESPTime datetime) {
                             datetime.second);
 };
 
-DateTimeCall &DateTimeCall::set_datetime(const std::string &datetime) {
+DateTimeCall &DateTimeCall::set_datetime(const char *datetime, size_t len) {
   ESPTime val{};
-  if (!ESPTime::strptime(datetime, val)) {
+  if (!ESPTime::strptime(datetime, len, val)) {
     ESP_LOGE(TAG, "Could not convert the time string to an ESPTime object");
     return *this;
   }
diff --git a/esphome/components/datetime/datetime_entity.h b/esphome/components/datetime/datetime_entity.h
index 018346b34b..b5b8cd677e 100644
--- a/esphome/components/datetime/datetime_entity.h
+++ b/esphome/components/datetime/datetime_entity.h
@@ -71,7 +71,11 @@ class DateTimeCall {
   void perform();
   DateTimeCall &set_datetime(uint16_t year, uint8_t month, uint8_t day, uint8_t hour, uint8_t minute, uint8_t second);
   DateTimeCall &set_datetime(ESPTime datetime);
-  DateTimeCall &set_datetime(const std::string &datetime);
+  DateTimeCall &set_datetime(const char *datetime, size_t len);
+  DateTimeCall &set_datetime(const char *datetime) { return this->set_datetime(datetime, strlen(datetime)); }
+  DateTimeCall &set_datetime(const std::string &datetime) {
+    return this->set_datetime(datetime.c_str(), datetime.size());
+  }
   DateTimeCall &set_datetime(time_t epoch_seconds);
 
   DateTimeCall &set_year(uint16_t year) {
diff --git a/esphome/components/datetime/time_entity.cpp b/esphome/components/datetime/time_entity.cpp
index d0b8875ed1..74e43fbbe7 100644
--- a/esphome/components/datetime/time_entity.cpp
+++ b/esphome/components/datetime/time_entity.cpp
@@ -74,9 +74,9 @@ TimeCall &TimeCall::set_time(uint8_t hour, uint8_t minute, uint8_t second) {
 
 TimeCall &TimeCall::set_time(ESPTime time) { return this->set_time(time.hour, time.minute, time.second); };
 
-TimeCall &TimeCall::set_time(const std::string &time) {
+TimeCall &TimeCall::set_time(const char *time, size_t len) {
   ESPTime val{};
-  if (!ESPTime::strptime(time, val)) {
+  if (!ESPTime::strptime(time, len, val)) {
     ESP_LOGE(TAG, "Could not convert the time string to an ESPTime object");
     return *this;
   }
diff --git a/esphome/components/datetime/time_entity.h b/esphome/components/datetime/time_entity.h
index d3be3130b1..e4bb113eb5 100644
--- a/esphome/components/datetime/time_entity.h
+++ b/esphome/components/datetime/time_entity.h
@@ -69,7 +69,9 @@ class TimeCall {
   void perform();
   TimeCall &set_time(uint8_t hour, uint8_t minute, uint8_t second);
   TimeCall &set_time(ESPTime time);
-  TimeCall &set_time(const std::string &time);
+  TimeCall &set_time(const char *time, size_t len);
+  TimeCall &set_time(const char *time) { return this->set_time(time, strlen(time)); }
+  TimeCall &set_time(const std::string &time) { return this->set_time(time.c_str(), time.size()); }
 
   TimeCall &set_hour(uint8_t hour) {
     this->hour_ = hour;
diff --git a/esphome/components/debug/debug_component.cpp b/esphome/components/debug/debug_component.cpp
index ae38fb2ccd..15f68c3a3b 100644
--- a/esphome/components/debug/debug_component.cpp
+++ b/esphome/components/debug/debug_component.cpp
@@ -30,7 +30,7 @@ void DebugComponent::dump_config() {
 
   char device_info_buffer[DEVICE_INFO_BUFFER_SIZE];
   ESP_LOGD(TAG, "ESPHome version %s", ESPHOME_VERSION);
-  size_t pos = buf_append(device_info_buffer, DEVICE_INFO_BUFFER_SIZE, 0, "%s", ESPHOME_VERSION);
+  size_t pos = buf_append_printf(device_info_buffer, DEVICE_INFO_BUFFER_SIZE, 0, "%s", ESPHOME_VERSION);
 
   this->free_heap_ = get_free_heap_();
   ESP_LOGD(TAG, "Free Heap Size: %" PRIu32 " bytes", this->free_heap_);
diff --git a/esphome/components/debug/debug_component.h b/esphome/components/debug/debug_component.h
index 6cf52d890c..e4f4bb36eb 100644
--- a/esphome/components/debug/debug_component.h
+++ b/esphome/components/debug/debug_component.h
@@ -5,12 +5,6 @@
 #include "esphome/core/helpers.h"
 #include "esphome/core/macros.h"
 #include <span>
-#include <cstdarg>
-#include <cstdio>
-#include <algorithm>
-#ifdef USE_ESP8266
-#include <pgmspace.h>
-#endif
 
 #ifdef USE_SENSOR
 #include "esphome/components/sensor/sensor.h"
@@ -25,40 +19,7 @@ namespace debug {
 static constexpr size_t DEVICE_INFO_BUFFER_SIZE = 256;
 static constexpr size_t RESET_REASON_BUFFER_SIZE = 128;
 
-#ifdef USE_ESP8266
-// ESP8266: Use vsnprintf_P to keep format strings in flash (PROGMEM)
-// Format strings must be wrapped with PSTR() macro
-inline size_t buf_append_p(char *buf, size_t size, size_t pos, PGM_P fmt, ...) {
-  if (pos >= size) {
-    return size;
-  }
-  va_list args;
-  va_start(args, fmt);
-  int written = vsnprintf_P(buf + pos, size - pos, fmt, args);
-  va_end(args);
-  if (written < 0) {
-    return pos;  // encoding error
-  }
-  return std::min(pos + static_cast<size_t>(written), size);
-}
-#define buf_append(buf, size, pos, fmt, ...) buf_append_p(buf, size, pos, PSTR(fmt), ##__VA_ARGS__)
-#else
-/// Safely append formatted string to buffer, returning new position (capped at size)
-__attribute__((format(printf, 4, 5))) inline size_t buf_append(char *buf, size_t size, size_t pos, const char *fmt,
-                                                               ...) {
-  if (pos >= size) {
-    return size;
-  }
-  va_list args;
-  va_start(args, fmt);
-  int written = vsnprintf(buf + pos, size - pos, fmt, args);
-  va_end(args);
-  if (written < 0) {
-    return pos;  // encoding error
-  }
-  return std::min(pos + static_cast<size_t>(written), size);
-}
-#endif
+// buf_append_printf is now provided by esphome/core/helpers.h
 
 class DebugComponent : public PollingComponent {
  public:
diff --git a/esphome/components/debug/debug_esp32.cpp b/esphome/components/debug/debug_esp32.cpp
index 8c41011f7d..aad4c7426c 100644
--- a/esphome/components/debug/debug_esp32.cpp
+++ b/esphome/components/debug/debug_esp32.cpp
@@ -173,8 +173,8 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
   uint32_t flash_size = ESP.getFlashChipSize() / 1024;       // NOLINT
   uint32_t flash_speed = ESP.getFlashChipSpeed() / 1000000;  // NOLINT
   ESP_LOGD(TAG, "Flash Chip: Size=%" PRIu32 "kB Speed=%" PRIu32 "MHz Mode=%s", flash_size, flash_speed, flash_mode);
-  pos = buf_append(buf, size, pos, "|Flash: %" PRIu32 "kB Speed:%" PRIu32 "MHz Mode:%s", flash_size, flash_speed,
-                   flash_mode);
+  pos = buf_append_printf(buf, size, pos, "|Flash: %" PRIu32 "kB Speed:%" PRIu32 "MHz Mode:%s", flash_size, flash_speed,
+                          flash_mode);
 #endif
 
   esp_chip_info_t info;
@@ -182,52 +182,52 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
   const char *model = ESPHOME_VARIANT;
 
   // Build features string
-  pos = buf_append(buf, size, pos, "|Chip: %s Features:", model);
+  pos = buf_append_printf(buf, size, pos, "|Chip: %s Features:", model);
   bool first_feature = true;
   for (const auto &feature : CHIP_FEATURES) {
     if (info.features & feature.bit) {
-      pos = buf_append(buf, size, pos, "%s%s", first_feature ? "" : ", ", feature.name);
+      pos = buf_append_printf(buf, size, pos, "%s%s", first_feature ? "" : ", ", feature.name);
       first_feature = false;
       info.features &= ~feature.bit;
     }
   }
   if (info.features != 0) {
-    pos = buf_append(buf, size, pos, "%sOther:0x%" PRIx32, first_feature ? "" : ", ", info.features);
+    pos = buf_append_printf(buf, size, pos, "%sOther:0x%" PRIx32, first_feature ? "" : ", ", info.features);
   }
   ESP_LOGD(TAG, "Chip: Model=%s, Cores=%u, Revision=%u", model, info.cores, info.revision);
-  pos = buf_append(buf, size, pos, " Cores:%u Revision:%u", info.cores, info.revision);
+  pos = buf_append_printf(buf, size, pos, " Cores:%u Revision:%u", info.cores, info.revision);
 
   uint32_t cpu_freq_mhz = arch_get_cpu_freq_hz() / 1000000;
   ESP_LOGD(TAG, "CPU Frequency: %" PRIu32 " MHz", cpu_freq_mhz);
-  pos = buf_append(buf, size, pos, "|CPU Frequency: %" PRIu32 " MHz", cpu_freq_mhz);
+  pos = buf_append_printf(buf, size, pos, "|CPU Frequency: %" PRIu32 " MHz", cpu_freq_mhz);
 
   // Framework detection
 #ifdef USE_ARDUINO
   ESP_LOGD(TAG, "Framework: Arduino");
-  pos = buf_append(buf, size, pos, "|Framework: Arduino");
+  pos = buf_append_printf(buf, size, pos, "|Framework: Arduino");
 #elif defined(USE_ESP32)
   ESP_LOGD(TAG, "Framework: ESP-IDF");
-  pos = buf_append(buf, size, pos, "|Framework: ESP-IDF");
+  pos = buf_append_printf(buf, size, pos, "|Framework: ESP-IDF");
 #else
   ESP_LOGW(TAG, "Framework: UNKNOWN");
-  pos = buf_append(buf, size, pos, "|Framework: UNKNOWN");
+  pos = buf_append_printf(buf, size, pos, "|Framework: UNKNOWN");
 #endif
 
   ESP_LOGD(TAG, "ESP-IDF Version: %s", esp_get_idf_version());
-  pos = buf_append(buf, size, pos, "|ESP-IDF: %s", esp_get_idf_version());
+  pos = buf_append_printf(buf, size, pos, "|ESP-IDF: %s", esp_get_idf_version());
 
   uint8_t mac[6];
   get_mac_address_raw(mac);
   ESP_LOGD(TAG, "EFuse MAC: %02X:%02X:%02X:%02X:%02X:%02X", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
-  pos = buf_append(buf, size, pos, "|EFuse MAC: %02X:%02X:%02X:%02X:%02X:%02X", mac[0], mac[1], mac[2], mac[3], mac[4],
-                   mac[5]);
+  pos = buf_append_printf(buf, size, pos, "|EFuse MAC: %02X:%02X:%02X:%02X:%02X:%02X", mac[0], mac[1], mac[2], mac[3],
+                          mac[4], mac[5]);
 
   char reason_buffer[RESET_REASON_BUFFER_SIZE];
   const char *reset_reason = get_reset_reason_(std::span<char, RESET_REASON_BUFFER_SIZE>(reason_buffer));
-  pos = buf_append(buf, size, pos, "|Reset: %s", reset_reason);
+  pos = buf_append_printf(buf, size, pos, "|Reset: %s", reset_reason);
 
   const char *wakeup_cause = get_wakeup_cause_(std::span<char, RESET_REASON_BUFFER_SIZE>(reason_buffer));
-  pos = buf_append(buf, size, pos, "|Wakeup: %s", wakeup_cause);
+  pos = buf_append_printf(buf, size, pos, "|Wakeup: %s", wakeup_cause);
 
   return pos;
 }
diff --git a/esphome/components/debug/debug_esp8266.cpp b/esphome/components/debug/debug_esp8266.cpp
index 274f77e20d..a4b6468b49 100644
--- a/esphome/components/debug/debug_esp8266.cpp
+++ b/esphome/components/debug/debug_esp8266.cpp
@@ -3,21 +3,80 @@
 #include "esphome/core/log.h"
 #include <Esp.h>
 
+extern "C" {
+#include <user_interface.h>
+
+// Global reset info struct populated by SDK at boot
+extern struct rst_info resetInfo;
+
+// Core version - either a string pointer or a version number to format as hex
+extern uint32_t core_version;
+extern const char *core_release;
+}
+
 namespace esphome {
 namespace debug {
 
 static const char *const TAG = "debug";
 
+// Get reset reason string from reason code (no heap allocation)
+// Returns LogString* pointing to flash (PROGMEM) on ESP8266
+static const LogString *get_reset_reason_str(uint32_t reason) {
+  switch (reason) {
+    case REASON_DEFAULT_RST:
+      return LOG_STR("Power On");
+    case REASON_WDT_RST:
+      return LOG_STR("Hardware Watchdog");
+    case REASON_EXCEPTION_RST:
+      return LOG_STR("Exception");
+    case REASON_SOFT_WDT_RST:
+      return LOG_STR("Software Watchdog");
+    case REASON_SOFT_RESTART:
+      return LOG_STR("Software/System restart");
+    case REASON_DEEP_SLEEP_AWAKE:
+      return LOG_STR("Deep-Sleep Wake");
+    case REASON_EXT_SYS_RST:
+      return LOG_STR("External System");
+    default:
+      return LOG_STR("Unknown");
+  }
+}
+
+// Size for core version hex buffer
+static constexpr size_t CORE_VERSION_BUFFER_SIZE = 12;
+
+// Get core version string (no heap allocation)
+// Returns either core_release directly or formats core_version as hex into provided buffer
+static const char *get_core_version_str(std::span<char, CORE_VERSION_BUFFER_SIZE> buffer) {
+  if (core_release != nullptr) {
+    return core_release;
+  }
+  snprintf_P(buffer.data(), CORE_VERSION_BUFFER_SIZE, PSTR("%08x"), core_version);
+  return buffer.data();
+}
+
+// Size for reset info buffer
+static constexpr size_t RESET_INFO_BUFFER_SIZE = 200;
+
+// Get detailed reset info string (no heap allocation)
+// For watchdog/exception resets, includes detailed exception info
+static const char *get_reset_info_str(std::span<char, RESET_INFO_BUFFER_SIZE> buffer, uint32_t reason) {
+  if (reason >= REASON_WDT_RST && reason <= REASON_SOFT_WDT_RST) {
+    snprintf_P(buffer.data(), RESET_INFO_BUFFER_SIZE,
+               PSTR("Fatal exception:%d flag:%d (%s) epc1:0x%08x epc2:0x%08x epc3:0x%08x excvaddr:0x%08x depc:0x%08x"),
+               static_cast<int>(resetInfo.exccause), static_cast<int>(reason),
+               LOG_STR_ARG(get_reset_reason_str(reason)), resetInfo.epc1, resetInfo.epc2, resetInfo.epc3,
+               resetInfo.excvaddr, resetInfo.depc);
+    return buffer.data();
+  }
+  return LOG_STR_ARG(get_reset_reason_str(reason));
+}
+
 const char *DebugComponent::get_reset_reason_(std::span<char, RESET_REASON_BUFFER_SIZE> buffer) {
-  char *buf = buffer.data();
-#if !defined(CLANG_TIDY)
-  String reason = ESP.getResetReason();  // NOLINT
-  snprintf_P(buf, RESET_REASON_BUFFER_SIZE, PSTR("%s"), reason.c_str());
-  return buf;
-#else
-  buf[0] = '\0';
-  return buf;
-#endif
+  // Copy from flash to provided buffer
+  strncpy_P(buffer.data(), (PGM_P) get_reset_reason_str(resetInfo.reason), RESET_REASON_BUFFER_SIZE - 1);
+  buffer[RESET_REASON_BUFFER_SIZE - 1] = '\0';
+  return buffer.data();
 }
 
 const char *DebugComponent::get_wakeup_cause_(std::span<char, RESET_REASON_BUFFER_SIZE> buffer) {
@@ -33,37 +92,42 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
   constexpr size_t size = DEVICE_INFO_BUFFER_SIZE;
   char *buf = buffer.data();
 
-  const char *flash_mode;
+  const LogString *flash_mode;
   switch (ESP.getFlashChipMode()) {  // NOLINT(readability-static-accessed-through-instance)
     case FM_QIO:
-      flash_mode = "QIO";
+      flash_mode = LOG_STR("QIO");
       break;
     case FM_QOUT:
-      flash_mode = "QOUT";
+      flash_mode = LOG_STR("QOUT");
       break;
     case FM_DIO:
-      flash_mode = "DIO";
+      flash_mode = LOG_STR("DIO");
       break;
     case FM_DOUT:
-      flash_mode = "DOUT";
+      flash_mode = LOG_STR("DOUT");
       break;
     default:
-      flash_mode = "UNKNOWN";
+      flash_mode = LOG_STR("UNKNOWN");
   }
-  uint32_t flash_size = ESP.getFlashChipSize() / 1024;       // NOLINT
-  uint32_t flash_speed = ESP.getFlashChipSpeed() / 1000000;  // NOLINT
-  ESP_LOGD(TAG, "Flash Chip: Size=%" PRIu32 "kB Speed=%" PRIu32 "MHz Mode=%s", flash_size, flash_speed, flash_mode);
-  pos = buf_append(buf, size, pos, "|Flash: %" PRIu32 "kB Speed:%" PRIu32 "MHz Mode:%s", flash_size, flash_speed,
-                   flash_mode);
+  uint32_t flash_size = ESP.getFlashChipSize() / 1024;       // NOLINT(readability-static-accessed-through-instance)
+  uint32_t flash_speed = ESP.getFlashChipSpeed() / 1000000;  // NOLINT(readability-static-accessed-through-instance)
+  ESP_LOGD(TAG, "Flash Chip: Size=%" PRIu32 "kB Speed=%" PRIu32 "MHz Mode=%s", flash_size, flash_speed,
+           LOG_STR_ARG(flash_mode));
+  pos = buf_append_printf(buf, size, pos, "|Flash: %" PRIu32 "kB Speed:%" PRIu32 "MHz Mode:%s", flash_size, flash_speed,
+                          LOG_STR_ARG(flash_mode));
 
-#if !defined(CLANG_TIDY)
   char reason_buffer[RESET_REASON_BUFFER_SIZE];
-  const char *reset_reason = get_reset_reason_(std::span<char, RESET_REASON_BUFFER_SIZE>(reason_buffer));
+  const char *reset_reason = get_reset_reason_(reason_buffer);
+  char core_version_buffer[CORE_VERSION_BUFFER_SIZE];
+  char reset_info_buffer[RESET_INFO_BUFFER_SIZE];
+  // NOLINTBEGIN(readability-static-accessed-through-instance)
   uint32_t chip_id = ESP.getChipId();
   uint8_t boot_version = ESP.getBootVersion();
   uint8_t boot_mode = ESP.getBootMode();
   uint8_t cpu_freq = ESP.getCpuFreqMHz();
   uint32_t flash_chip_id = ESP.getFlashChipId();
+  const char *sdk_version = ESP.getSdkVersion();
+  // NOLINTEND(readability-static-accessed-through-instance)
 
   ESP_LOGD(TAG,
            "Chip ID: 0x%08" PRIX32 "\n"
@@ -74,19 +138,18 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
            "Flash Chip ID=0x%08" PRIX32 "\n"
            "Reset Reason: %s\n"
            "Reset Info: %s",
-           chip_id, ESP.getSdkVersion(), ESP.getCoreVersion().c_str(), boot_version, boot_mode, cpu_freq, flash_chip_id,
-           reset_reason, ESP.getResetInfo().c_str());
+           chip_id, sdk_version, get_core_version_str(core_version_buffer), boot_version, boot_mode, cpu_freq,
+           flash_chip_id, reset_reason, get_reset_info_str(reset_info_buffer, resetInfo.reason));
 
-  pos = buf_append(buf, size, pos, "|Chip: 0x%08" PRIX32, chip_id);
-  pos = buf_append(buf, size, pos, "|SDK: %s", ESP.getSdkVersion());
-  pos = buf_append(buf, size, pos, "|Core: %s", ESP.getCoreVersion().c_str());
-  pos = buf_append(buf, size, pos, "|Boot: %u", boot_version);
-  pos = buf_append(buf, size, pos, "|Mode: %u", boot_mode);
-  pos = buf_append(buf, size, pos, "|CPU: %u", cpu_freq);
-  pos = buf_append(buf, size, pos, "|Flash: 0x%08" PRIX32, flash_chip_id);
-  pos = buf_append(buf, size, pos, "|Reset: %s", reset_reason);
-  pos = buf_append(buf, size, pos, "|%s", ESP.getResetInfo().c_str());
-#endif
+  pos = buf_append_printf(buf, size, pos, "|Chip: 0x%08" PRIX32, chip_id);
+  pos = buf_append_printf(buf, size, pos, "|SDK: %s", sdk_version);
+  pos = buf_append_printf(buf, size, pos, "|Core: %s", get_core_version_str(core_version_buffer));
+  pos = buf_append_printf(buf, size, pos, "|Boot: %u", boot_version);
+  pos = buf_append_printf(buf, size, pos, "|Mode: %u", boot_mode);
+  pos = buf_append_printf(buf, size, pos, "|CPU: %u", cpu_freq);
+  pos = buf_append_printf(buf, size, pos, "|Flash: 0x%08" PRIX32, flash_chip_id);
+  pos = buf_append_printf(buf, size, pos, "|Reset: %s", reset_reason);
+  pos = buf_append_printf(buf, size, pos, "|%s", get_reset_info_str(reset_info_buffer, resetInfo.reason));
 
   return pos;
 }
diff --git a/esphome/components/debug/debug_libretiny.cpp b/esphome/components/debug/debug_libretiny.cpp
index aae27c8ca2..14bbdb945a 100644
--- a/esphome/components/debug/debug_libretiny.cpp
+++ b/esphome/components/debug/debug_libretiny.cpp
@@ -36,12 +36,12 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
            lt_get_version(), lt_cpu_get_model_name(), lt_cpu_get_model(), lt_cpu_get_freq_mhz(), mac_id,
            lt_get_board_code(), flash_kib, ram_kib, reset_reason);
 
-  pos = buf_append(buf, size, pos, "|Version: %s", LT_BANNER_STR + 10);
-  pos = buf_append(buf, size, pos, "|Reset Reason: %s", reset_reason);
-  pos = buf_append(buf, size, pos, "|Chip Name: %s", lt_cpu_get_model_name());
-  pos = buf_append(buf, size, pos, "|Chip ID: 0x%06" PRIX32, mac_id);
-  pos = buf_append(buf, size, pos, "|Flash: %" PRIu32 " KiB", flash_kib);
-  pos = buf_append(buf, size, pos, "|RAM: %" PRIu32 " KiB", ram_kib);
+  pos = buf_append_printf(buf, size, pos, "|Version: %s", LT_BANNER_STR + 10);
+  pos = buf_append_printf(buf, size, pos, "|Reset Reason: %s", reset_reason);
+  pos = buf_append_printf(buf, size, pos, "|Chip Name: %s", lt_cpu_get_model_name());
+  pos = buf_append_printf(buf, size, pos, "|Chip ID: 0x%06" PRIX32, mac_id);
+  pos = buf_append_printf(buf, size, pos, "|Flash: %" PRIu32 " KiB", flash_kib);
+  pos = buf_append_printf(buf, size, pos, "|RAM: %" PRIu32 " KiB", ram_kib);
 
   return pos;
 }
diff --git a/esphome/components/debug/debug_rp2040.cpp b/esphome/components/debug/debug_rp2040.cpp
index a426a73bc2..c9d41942db 100644
--- a/esphome/components/debug/debug_rp2040.cpp
+++ b/esphome/components/debug/debug_rp2040.cpp
@@ -19,7 +19,7 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
 
   uint32_t cpu_freq = rp2040.f_cpu();
   ESP_LOGD(TAG, "CPU Frequency: %" PRIu32, cpu_freq);
-  pos = buf_append(buf, size, pos, "|CPU Frequency: %" PRIu32, cpu_freq);
+  pos = buf_append_printf(buf, size, pos, "|CPU Frequency: %" PRIu32, cpu_freq);
 
   return pos;
 }
diff --git a/esphome/components/debug/debug_zephyr.cpp b/esphome/components/debug/debug_zephyr.cpp
index 3f9af03b2b..0291cc3061 100644
--- a/esphome/components/debug/debug_zephyr.cpp
+++ b/esphome/components/debug/debug_zephyr.cpp
@@ -20,9 +20,9 @@ static size_t append_reset_reason(char *buf, size_t size, size_t pos, bool set,
     return pos;
   }
   if (pos > 0) {
-    pos = buf_append(buf, size, pos, ", ");
+    pos = buf_append_printf(buf, size, pos, ", ");
   }
-  return buf_append(buf, size, pos, "%s", reason);
+  return buf_append_printf(buf, size, pos, "%s", reason);
 }
 
 static inline uint32_t read_mem_u32(uintptr_t addr) {
@@ -132,6 +132,26 @@ void DebugComponent::log_partition_info_() {
   flash_area_foreach(fa_cb, nullptr);
 }
 
+static const char *regout0_to_str(uint32_t value) {
+  switch (value) {
+    case (UICR_REGOUT0_VOUT_DEFAULT):
+      return "1.8V (default)";
+    case (UICR_REGOUT0_VOUT_1V8):
+      return "1.8V";
+    case (UICR_REGOUT0_VOUT_2V1):
+      return "2.1V";
+    case (UICR_REGOUT0_VOUT_2V4):
+      return "2.4V";
+    case (UICR_REGOUT0_VOUT_2V7):
+      return "2.7V";
+    case (UICR_REGOUT0_VOUT_3V0):
+      return "3.0V";
+    case (UICR_REGOUT0_VOUT_3V3):
+      return "3.3V";
+  }
+  return "???V";
+}
+
 size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE> buffer, size_t pos) {
   constexpr size_t size = DEVICE_INFO_BUFFER_SIZE;
   char *buf = buffer.data();
@@ -140,48 +160,28 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
   const char *supply_status =
       (nrf_power_mainregstatus_get(NRF_POWER) == NRF_POWER_MAINREGSTATUS_NORMAL) ? "Normal voltage." : "High voltage.";
   ESP_LOGD(TAG, "Main supply status: %s", supply_status);
-  pos = buf_append(buf, size, pos, "|Main supply status: %s", supply_status);
+  pos = buf_append_printf(buf, size, pos, "|Main supply status: %s", supply_status);
 
   // Regulator stage 0
   if (nrf_power_mainregstatus_get(NRF_POWER) == NRF_POWER_MAINREGSTATUS_HIGH) {
     const char *reg0_type = nrf_power_dcdcen_vddh_get(NRF_POWER) ? "DC/DC" : "LDO";
-    const char *reg0_voltage;
-    switch (NRF_UICR->REGOUT0 & UICR_REGOUT0_VOUT_Msk) {
-      case (UICR_REGOUT0_VOUT_DEFAULT << UICR_REGOUT0_VOUT_Pos):
-        reg0_voltage = "1.8V (default)";
-        break;
-      case (UICR_REGOUT0_VOUT_1V8 << UICR_REGOUT0_VOUT_Pos):
-        reg0_voltage = "1.8V";
-        break;
-      case (UICR_REGOUT0_VOUT_2V1 << UICR_REGOUT0_VOUT_Pos):
-        reg0_voltage = "2.1V";
-        break;
-      case (UICR_REGOUT0_VOUT_2V4 << UICR_REGOUT0_VOUT_Pos):
-        reg0_voltage = "2.4V";
-        break;
-      case (UICR_REGOUT0_VOUT_2V7 << UICR_REGOUT0_VOUT_Pos):
-        reg0_voltage = "2.7V";
-        break;
-      case (UICR_REGOUT0_VOUT_3V0 << UICR_REGOUT0_VOUT_Pos):
-        reg0_voltage = "3.0V";
-        break;
-      case (UICR_REGOUT0_VOUT_3V3 << UICR_REGOUT0_VOUT_Pos):
-        reg0_voltage = "3.3V";
-        break;
-      default:
-        reg0_voltage = "???V";
-    }
+    const char *reg0_voltage = regout0_to_str((NRF_UICR->REGOUT0 & UICR_REGOUT0_VOUT_Msk) >> UICR_REGOUT0_VOUT_Pos);
     ESP_LOGD(TAG, "Regulator stage 0: %s, %s", reg0_type, reg0_voltage);
-    pos = buf_append(buf, size, pos, "|Regulator stage 0: %s, %s", reg0_type, reg0_voltage);
+    pos = buf_append_printf(buf, size, pos, "|Regulator stage 0: %s, %s", reg0_type, reg0_voltage);
+#ifdef USE_NRF52_REG0_VOUT
+    if ((NRF_UICR->REGOUT0 & UICR_REGOUT0_VOUT_Msk) >> UICR_REGOUT0_VOUT_Pos != USE_NRF52_REG0_VOUT) {
+      ESP_LOGE(TAG, "Regulator stage 0: expected %s", regout0_to_str(USE_NRF52_REG0_VOUT));
+    }
+#endif
   } else {
     ESP_LOGD(TAG, "Regulator stage 0: disabled");
-    pos = buf_append(buf, size, pos, "|Regulator stage 0: disabled");
+    pos = buf_append_printf(buf, size, pos, "|Regulator stage 0: disabled");
   }
 
   // Regulator stage 1
   const char *reg1_type = nrf_power_dcdcen_get(NRF_POWER) ? "DC/DC" : "LDO";
   ESP_LOGD(TAG, "Regulator stage 1: %s", reg1_type);
-  pos = buf_append(buf, size, pos, "|Regulator stage 1: %s", reg1_type);
+  pos = buf_append_printf(buf, size, pos, "|Regulator stage 1: %s", reg1_type);
 
   // USB power state
   const char *usb_state;
@@ -195,7 +195,7 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
     usb_state = "disconnected";
   }
   ESP_LOGD(TAG, "USB power state: %s", usb_state);
-  pos = buf_append(buf, size, pos, "|USB power state: %s", usb_state);
+  pos = buf_append_printf(buf, size, pos, "|USB power state: %s", usb_state);
 
   // Power-fail comparator
   bool enabled;
@@ -300,14 +300,14 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
           break;
       }
       ESP_LOGD(TAG, "Power-fail comparator: %s, VDDH: %s", pof_voltage, vddh_voltage);
-      pos = buf_append(buf, size, pos, "|Power-fail comparator: %s, VDDH: %s", pof_voltage, vddh_voltage);
+      pos = buf_append_printf(buf, size, pos, "|Power-fail comparator: %s, VDDH: %s", pof_voltage, vddh_voltage);
     } else {
       ESP_LOGD(TAG, "Power-fail comparator: %s", pof_voltage);
-      pos = buf_append(buf, size, pos, "|Power-fail comparator: %s", pof_voltage);
+      pos = buf_append_printf(buf, size, pos, "|Power-fail comparator: %s", pof_voltage);
     }
   } else {
     ESP_LOGD(TAG, "Power-fail comparator: disabled");
-    pos = buf_append(buf, size, pos, "|Power-fail comparator: disabled");
+    pos = buf_append_printf(buf, size, pos, "|Power-fail comparator: disabled");
   }
 
   auto package = [](uint32_t value) {
diff --git a/esphome/components/dfrobot_sen0395/commands.cpp b/esphome/components/dfrobot_sen0395/commands.cpp
index 8bb6ddf942..2c44c6fba9 100644
--- a/esphome/components/dfrobot_sen0395/commands.cpp
+++ b/esphome/components/dfrobot_sen0395/commands.cpp
@@ -127,7 +127,9 @@ DetRangeCfgCommand::DetRangeCfgCommand(float min1, float max1, float min2, float
     this->min2_ = min2 = this->max2_ = max2 = this->min3_ = min3 = this->max3_ = max3 = this->min4_ = min4 =
         this->max4_ = max4 = -1;
 
-    this->cmd_ = str_sprintf("detRangeCfg -1 %.0f %.0f", min1 / 0.15, max1 / 0.15);
+    char buf[72];  // max 72: "detRangeCfg -1 "(15) + 8 * (float(5) + space(1)) + null
+    snprintf(buf, sizeof(buf), "detRangeCfg -1 %.0f %.0f", min1 / 0.15, max1 / 0.15);
+    this->cmd_ = buf;
   } else if (min3 < 0 || max3 < 0) {
     this->min1_ = min1 = round(min1 / 0.15) * 0.15;
     this->max1_ = max1 = round(max1 / 0.15) * 0.15;
@@ -135,7 +137,10 @@ DetRangeCfgCommand::DetRangeCfgCommand(float min1, float max1, float min2, float
     this->max2_ = max2 = round(max2 / 0.15) * 0.15;
     this->min3_ = min3 = this->max3_ = max3 = this->min4_ = min4 = this->max4_ = max4 = -1;
 
-    this->cmd_ = str_sprintf("detRangeCfg -1 %.0f %.0f %.0f %.0f", min1 / 0.15, max1 / 0.15, min2 / 0.15, max2 / 0.15);
+    char buf[72];  // max 72: "detRangeCfg -1 "(15) + 8 * (float(5) + space(1)) + null
+    snprintf(buf, sizeof(buf), "detRangeCfg -1 %.0f %.0f %.0f %.0f", min1 / 0.15, max1 / 0.15, min2 / 0.15,
+             max2 / 0.15);
+    this->cmd_ = buf;
   } else if (min4 < 0 || max4 < 0) {
     this->min1_ = min1 = round(min1 / 0.15) * 0.15;
     this->max1_ = max1 = round(max1 / 0.15) * 0.15;
@@ -145,9 +150,10 @@ DetRangeCfgCommand::DetRangeCfgCommand(float min1, float max1, float min2, float
     this->max3_ = max3 = round(max3 / 0.15) * 0.15;
     this->min4_ = min4 = this->max4_ = max4 = -1;
 
-    this->cmd_ = str_sprintf("detRangeCfg -1 "
-                             "%.0f %.0f %.0f %.0f %.0f %.0f",
-                             min1 / 0.15, max1 / 0.15, min2 / 0.15, max2 / 0.15, min3 / 0.15, max3 / 0.15);
+    char buf[72];  // max 72: "detRangeCfg -1 "(15) + 8 * (float(5) + space(1)) + null
+    snprintf(buf, sizeof(buf), "detRangeCfg -1 %.0f %.0f %.0f %.0f %.0f %.0f", min1 / 0.15, max1 / 0.15, min2 / 0.15,
+             max2 / 0.15, min3 / 0.15, max3 / 0.15);
+    this->cmd_ = buf;
   } else {
     this->min1_ = min1 = round(min1 / 0.15) * 0.15;
     this->max1_ = max1 = round(max1 / 0.15) * 0.15;
@@ -158,10 +164,10 @@ DetRangeCfgCommand::DetRangeCfgCommand(float min1, float max1, float min2, float
     this->min4_ = min4 = round(min4 / 0.15) * 0.15;
     this->max4_ = max4 = round(max4 / 0.15) * 0.15;
 
-    this->cmd_ = str_sprintf("detRangeCfg -1 "
-                             "%.0f %.0f %.0f %.0f %.0f %.0f %.0f %.0f",
-                             min1 / 0.15, max1 / 0.15, min2 / 0.15, max2 / 0.15, min3 / 0.15, max3 / 0.15, min4 / 0.15,
-                             max4 / 0.15);
+    char buf[72];  // max 72: "detRangeCfg -1 "(15) + 8 * (float(5) + space(1)) + null
+    snprintf(buf, sizeof(buf), "detRangeCfg -1 %.0f %.0f %.0f %.0f %.0f %.0f %.0f %.0f", min1 / 0.15, max1 / 0.15,
+             min2 / 0.15, max2 / 0.15, min3 / 0.15, max3 / 0.15, min4 / 0.15, max4 / 0.15);
+    this->cmd_ = buf;
   }
 
   this->min1_ = min1;
@@ -203,7 +209,10 @@ SetLatencyCommand::SetLatencyCommand(float delay_after_detection, float delay_af
   delay_after_disappear = std::round(delay_after_disappear / 0.025f) * 0.025f;
   this->delay_after_detection_ = clamp(delay_after_detection, 0.0f, 1638.375f);
   this->delay_after_disappear_ = clamp(delay_after_disappear, 0.0f, 1638.375f);
-  this->cmd_ = str_sprintf("setLatency %.03f %.03f", this->delay_after_detection_, this->delay_after_disappear_);
+  // max 32: "setLatency "(11) + float(8) + " "(1) + float(8) + null, rounded to 32
+  char buf[32];
+  snprintf(buf, sizeof(buf), "setLatency %.03f %.03f", this->delay_after_detection_, this->delay_after_disappear_);
+  this->cmd_ = buf;
 };
 
 uint8_t SetLatencyCommand::on_message(std::string &message) {
diff --git a/esphome/components/dfrobot_sen0395/commands.h b/esphome/components/dfrobot_sen0395/commands.h
index cf3ba50be0..3b0551b184 100644
--- a/esphome/components/dfrobot_sen0395/commands.h
+++ b/esphome/components/dfrobot_sen0395/commands.h
@@ -75,8 +75,8 @@ class SetLatencyCommand : public Command {
 class SensorCfgStartCommand : public Command {
  public:
   SensorCfgStartCommand(bool startup_mode) : startup_mode_(startup_mode) {
-    char tmp_cmd[20] = {0};
-    sprintf(tmp_cmd, "sensorCfgStart %d", startup_mode);
+    char tmp_cmd[20];  // "sensorCfgStart " (15) + "0/1" (1) + null = 17
+    buf_append_printf(tmp_cmd, sizeof(tmp_cmd), 0, "sensorCfgStart %d", startup_mode);
     cmd_ = std::string(tmp_cmd);
   }
   uint8_t on_message(std::string &message) override;
@@ -142,8 +142,8 @@ class SensitivityCommand : public Command {
   SensitivityCommand(uint8_t sensitivity) : sensitivity_(sensitivity) {
     if (sensitivity > 9)
       sensitivity_ = sensitivity = 9;
-    char tmp_cmd[20] = {0};
-    sprintf(tmp_cmd, "setSensitivity %d", sensitivity);
+    char tmp_cmd[20];  // "setSensitivity " (15) + "0-9" (1) + null = 17
+    buf_append_printf(tmp_cmd, sizeof(tmp_cmd), 0, "setSensitivity %d", sensitivity);
     cmd_ = std::string(tmp_cmd);
   };
   uint8_t on_message(std::string &message) override;
diff --git a/esphome/components/dsmr/__init__.py b/esphome/components/dsmr/__init__.py
index 0ba68daf5d..386da3ce21 100644
--- a/esphome/components/dsmr/__init__.py
+++ b/esphome/components/dsmr/__init__.py
@@ -25,29 +25,13 @@ dsmr_ns = cg.esphome_ns.namespace("esphome::dsmr")
 Dsmr = dsmr_ns.class_("Dsmr", cg.Component, uart.UARTDevice)
 
 
-def _validate_key(value):
-    value = cv.string_strict(value)
-    parts = [value[i : i + 2] for i in range(0, len(value), 2)]
-    if len(parts) != 16:
-        raise cv.Invalid("Decryption key must consist of 16 hexadecimal numbers")
-    parts_int = []
-    if any(len(part) != 2 for part in parts):
-        raise cv.Invalid("Decryption key must be format XX")
-    for part in parts:
-        try:
-            parts_int.append(int(part, 16))
-        except ValueError:
-            # pylint: disable=raise-missing-from
-            raise cv.Invalid("Decryption key must be hex values from 00 to FF")
-
-    return "".join(f"{part:02X}" for part in parts_int)
-
-
 CONFIG_SCHEMA = cv.All(
     cv.Schema(
         {
             cv.GenerateID(): cv.declare_id(Dsmr),
-            cv.Optional(CONF_DECRYPTION_KEY): _validate_key,
+            cv.Optional(CONF_DECRYPTION_KEY): lambda value: cv.bind_key(
+                value, name="Decryption key"
+            ),
             cv.Optional(CONF_CRC_CHECK, default=True): cv.boolean,
             cv.Optional(CONF_GAS_MBUS_ID, default=1): cv.int_,
             cv.Optional(CONF_WATER_MBUS_ID, default=2): cv.int_,
diff --git a/esphome/components/dsmr/dsmr.cpp b/esphome/components/dsmr/dsmr.cpp
index 5c62aa93ab..c78d37bf5e 100644
--- a/esphome/components/dsmr/dsmr.cpp
+++ b/esphome/components/dsmr/dsmr.cpp
@@ -1,4 +1,5 @@
 #include "dsmr.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
 #include <AES.h>
@@ -294,8 +295,8 @@ void Dsmr::dump_config() {
   DSMR_TEXT_SENSOR_LIST(DSMR_LOG_TEXT_SENSOR, )
 }
 
-void Dsmr::set_decryption_key(const std::string &decryption_key) {
-  if (decryption_key.empty()) {
+void Dsmr::set_decryption_key(const char *decryption_key) {
+  if (decryption_key == nullptr || decryption_key[0] == '\0') {
     ESP_LOGI(TAG, "Disabling decryption");
     this->decryption_key_.clear();
     if (this->crypt_telegram_ != nullptr) {
@@ -305,21 +306,15 @@ void Dsmr::set_decryption_key(const std::string &decryption_key) {
     return;
   }
 
-  if (decryption_key.length() != 32) {
-    ESP_LOGE(TAG, "Error, decryption key must be 32 character long");
+  if (!parse_hex(decryption_key, this->decryption_key_, 16)) {
+    ESP_LOGE(TAG, "Error, decryption key must be 32 hex characters");
+    this->decryption_key_.clear();
     return;
   }
-  this->decryption_key_.clear();
 
   ESP_LOGI(TAG, "Decryption key is set");
   // Verbose level prints decryption key
-  ESP_LOGV(TAG, "Using decryption key: %s", decryption_key.c_str());
-
-  char temp[3] = {0};
-  for (int i = 0; i < 16; i++) {
-    strncpy(temp, &(decryption_key.c_str()[i * 2]), 2);
-    this->decryption_key_.push_back(std::strtoul(temp, nullptr, 16));
-  }
+  ESP_LOGV(TAG, "Using decryption key: %s", decryption_key);
 
   if (this->crypt_telegram_ == nullptr) {
     this->crypt_telegram_ = new uint8_t[this->max_telegram_len_];  // NOLINT
diff --git a/esphome/components/dsmr/dsmr.h b/esphome/components/dsmr/dsmr.h
index 56ba75b5fa..b7e05a22b3 100644
--- a/esphome/components/dsmr/dsmr.h
+++ b/esphome/components/dsmr/dsmr.h
@@ -63,7 +63,7 @@ class Dsmr : public Component, public uart::UARTDevice {
 
   void dump_config() override;
 
-  void set_decryption_key(const std::string &decryption_key);
+  void set_decryption_key(const char *decryption_key);
   void set_max_telegram_length(size_t length) { this->max_telegram_len_ = length; }
   void set_request_pin(GPIOPin *request_pin) { this->request_pin_ = request_pin; }
   void set_request_interval(uint32_t interval) { this->request_interval_ = interval; }
diff --git a/esphome/components/epaper_spi/display.py b/esphome/components/epaper_spi/display.py
index a77e291237..8cc7b2663c 100644
--- a/esphome/components/epaper_spi/display.py
+++ b/esphome/components/epaper_spi/display.py
@@ -190,7 +190,7 @@ async def to_code(config):
     # Rotation is handled by setting the transform
     display_config = {k: v for k, v in config.items() if k != CONF_ROTATION}
     await display.register_display(var, display_config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/esp32/__init__.py b/esphome/components/esp32/__init__.py
index 45fe8d1c26..da49fdc070 100644
--- a/esphome/components/esp32/__init__.py
+++ b/esphome/components/esp32/__init__.py
@@ -34,6 +34,7 @@ from esphome.const import (
     KEY_CORE,
     KEY_FRAMEWORK_VERSION,
     KEY_NAME,
+    KEY_NATIVE_IDF,
     KEY_TARGET_FRAMEWORK,
     KEY_TARGET_PLATFORM,
     PLATFORM_ESP32,
@@ -53,6 +54,7 @@ from .const import (  # noqa
     KEY_COMPONENTS,
     KEY_ESP32,
     KEY_EXTRA_BUILD_FILES,
+    KEY_FLASH_SIZE,
     KEY_PATH,
     KEY_REF,
     KEY_REPO,
@@ -180,6 +182,12 @@ def set_core_data(config):
             path=[CONF_CPU_FREQUENCY],
         )
 
+    if variant == VARIANT_ESP32P4 and cpu_frequency == "400MHZ":
+        _LOGGER.warning(
+            "400MHz on ESP32-P4 is experimental and may not boot. "
+            "Consider using 360MHz instead. See https://github.com/esphome/esphome/issues/13425"
+        )
+
     CORE.data[KEY_ESP32] = {}
     CORE.data[KEY_CORE][KEY_TARGET_PLATFORM] = PLATFORM_ESP32
     conf = config[CONF_FRAMEWORK]
@@ -199,6 +207,7 @@ def set_core_data(config):
     )
 
     CORE.data[KEY_ESP32][KEY_BOARD] = config[CONF_BOARD]
+    CORE.data[KEY_ESP32][KEY_FLASH_SIZE] = config[CONF_FLASH_SIZE]
     CORE.data[KEY_ESP32][KEY_VARIANT] = variant
     CORE.data[KEY_ESP32][KEY_EXTRA_BUILD_FILES] = {}
 
@@ -339,7 +348,12 @@ def add_extra_build_file(filename: str, path: Path) -> bool:
 def _format_framework_arduino_version(ver: cv.Version) -> str:
     # format the given arduino (https://github.com/espressif/arduino-esp32/releases) version to
     # a PIO pioarduino/framework-arduinoespressif32 value
-    return f"pioarduino/framework-arduinoespressif32@https://github.com/espressif/arduino-esp32/releases/download/{str(ver)}/esp32-{str(ver)}.zip"
+    # 3.3.6+ changed filename from esp32-{ver}.zip to esp32-core-{ver}.tar.xz
+    if ver >= cv.Version(3, 3, 6):
+        filename = f"esp32-core-{ver}.tar.xz"
+    else:
+        filename = f"esp32-{ver}.zip"
+    return f"pioarduino/framework-arduinoespressif32@https://github.com/espressif/arduino-esp32/releases/download/{ver}/{filename}"
 
 
 def _format_framework_espidf_version(ver: cv.Version, release: str) -> str:
@@ -374,11 +388,12 @@ def _is_framework_url(source: str) -> bool:
 # The default/recommended arduino framework version
 #  - https://github.com/espressif/arduino-esp32/releases
 ARDUINO_FRAMEWORK_VERSION_LOOKUP = {
-    "recommended": cv.Version(3, 3, 5),
-    "latest": cv.Version(3, 3, 5),
-    "dev": cv.Version(3, 3, 5),
+    "recommended": cv.Version(3, 3, 6),
+    "latest": cv.Version(3, 3, 6),
+    "dev": cv.Version(3, 3, 6),
 }
 ARDUINO_PLATFORM_VERSION_LOOKUP = {
+    cv.Version(3, 3, 6): cv.Version(55, 3, 36),
     cv.Version(3, 3, 5): cv.Version(55, 3, 35),
     cv.Version(3, 3, 4): cv.Version(55, 3, 31, "2"),
     cv.Version(3, 3, 3): cv.Version(55, 3, 31, "2"),
@@ -396,6 +411,7 @@ ARDUINO_PLATFORM_VERSION_LOOKUP = {
 # These versions correspond to pioarduino/esp-idf releases
 # See: https://github.com/pioarduino/esp-idf/releases
 ARDUINO_IDF_VERSION_LOOKUP = {
+    cv.Version(3, 3, 6): cv.Version(5, 5, 2),
     cv.Version(3, 3, 5): cv.Version(5, 5, 2),
     cv.Version(3, 3, 4): cv.Version(5, 5, 1),
     cv.Version(3, 3, 3): cv.Version(5, 5, 1),
@@ -418,7 +434,7 @@ ESP_IDF_FRAMEWORK_VERSION_LOOKUP = {
     "dev": cv.Version(5, 5, 2),
 }
 ESP_IDF_PLATFORM_VERSION_LOOKUP = {
-    cv.Version(5, 5, 2): cv.Version(55, 3, 35),
+    cv.Version(5, 5, 2): cv.Version(55, 3, 36),
     cv.Version(5, 5, 1): cv.Version(55, 3, 31, "2"),
     cv.Version(5, 5, 0): cv.Version(55, 3, 31, "2"),
     cv.Version(5, 4, 3): cv.Version(55, 3, 32),
@@ -435,9 +451,9 @@ ESP_IDF_PLATFORM_VERSION_LOOKUP = {
 # The platform-espressif32 version
 #  - https://github.com/pioarduino/platform-espressif32/releases
 PLATFORM_VERSION_LOOKUP = {
-    "recommended": cv.Version(55, 3, 35),
-    "latest": cv.Version(55, 3, 35),
-    "dev": cv.Version(55, 3, 35),
+    "recommended": cv.Version(55, 3, 36),
+    "latest": cv.Version(55, 3, 36),
+    "dev": cv.Version(55, 3, 36),
 }
 
 
@@ -962,12 +978,54 @@ async def _add_yaml_idf_components(components: list[ConfigType]):
 
 
 async def to_code(config):
-    cg.add_platformio_option("board", config[CONF_BOARD])
-    cg.add_platformio_option("board_upload.flash_size", config[CONF_FLASH_SIZE])
-    cg.add_platformio_option(
-        "board_upload.maximum_size",
-        int(config[CONF_FLASH_SIZE].removesuffix("MB")) * 1024 * 1024,
-    )
+    framework_ver: cv.Version = CORE.data[KEY_CORE][KEY_FRAMEWORK_VERSION]
+    conf = config[CONF_FRAMEWORK]
+
+    # Check if using native ESP-IDF build (--native-idf)
+    use_platformio = not CORE.data.get(KEY_NATIVE_IDF, False)
+    if use_platformio:
+        # Clear IDF environment variables to avoid conflicts with PlatformIO's ESP-IDF
+        # but keep them when using --native-idf for native ESP-IDF builds
+        for clean_var in ("IDF_PATH", "IDF_TOOLS_PATH"):
+            os.environ.pop(clean_var, None)
+
+        cg.add_platformio_option("lib_ldf_mode", "off")
+        cg.add_platformio_option("lib_compat_mode", "strict")
+        cg.add_platformio_option("platform", conf[CONF_PLATFORM_VERSION])
+        cg.add_platformio_option("board", config[CONF_BOARD])
+        cg.add_platformio_option("board_upload.flash_size", config[CONF_FLASH_SIZE])
+        cg.add_platformio_option(
+            "board_upload.maximum_size",
+            int(config[CONF_FLASH_SIZE].removesuffix("MB")) * 1024 * 1024,
+        )
+
+        if CONF_SOURCE in conf:
+            cg.add_platformio_option("platform_packages", [conf[CONF_SOURCE]])
+
+        add_extra_script(
+            "pre",
+            "pre_build.py",
+            Path(__file__).parent / "pre_build.py.script",
+        )
+
+        add_extra_script(
+            "post",
+            "post_build.py",
+            Path(__file__).parent / "post_build.py.script",
+        )
+
+        # In testing mode, add IRAM fix script to allow linking grouped component tests
+        # Similar to ESP8266's approach but for ESP-IDF
+        if CORE.testing_mode:
+            cg.add_build_flag("-DESPHOME_TESTING_MODE")
+            add_extra_script(
+                "pre",
+                "iram_fix.py",
+                Path(__file__).parent / "iram_fix.py.script",
+            )
+    else:
+        cg.add_build_flag("-Wno-error=format")
+
     cg.set_cpp_standard("gnu++20")
     cg.add_build_flag("-DUSE_ESP32")
     cg.add_build_flag("-Wl,-z,noexecstack")
@@ -977,79 +1035,49 @@ async def to_code(config):
     cg.add_define("ESPHOME_VARIANT", VARIANT_FRIENDLY[variant])
     cg.add_define(ThreadModel.MULTI_ATOMICS)
 
-    cg.add_platformio_option("lib_ldf_mode", "off")
-    cg.add_platformio_option("lib_compat_mode", "strict")
-
-    framework_ver: cv.Version = CORE.data[KEY_CORE][KEY_FRAMEWORK_VERSION]
-
-    conf = config[CONF_FRAMEWORK]
-    cg.add_platformio_option("platform", conf[CONF_PLATFORM_VERSION])
-    if CONF_SOURCE in conf:
-        cg.add_platformio_option("platform_packages", [conf[CONF_SOURCE]])
-
     if conf[CONF_ADVANCED][CONF_IGNORE_EFUSE_CUSTOM_MAC]:
         cg.add_define("USE_ESP32_IGNORE_EFUSE_CUSTOM_MAC")
 
-    for clean_var in ("IDF_PATH", "IDF_TOOLS_PATH"):
-        os.environ.pop(clean_var, None)
-
     # Set the location of the IDF component manager cache
     os.environ["IDF_COMPONENT_CACHE_PATH"] = str(
         CORE.relative_internal_path(".espressif")
     )
 
-    add_extra_script(
-        "pre",
-        "pre_build.py",
-        Path(__file__).parent / "pre_build.py.script",
-    )
-
-    add_extra_script(
-        "post",
-        "post_build.py",
-        Path(__file__).parent / "post_build.py.script",
-    )
-
-    # In testing mode, add IRAM fix script to allow linking grouped component tests
-    # Similar to ESP8266's approach but for ESP-IDF
-    if CORE.testing_mode:
-        cg.add_build_flag("-DESPHOME_TESTING_MODE")
-        add_extra_script(
-            "pre",
-            "iram_fix.py",
-            Path(__file__).parent / "iram_fix.py.script",
-        )
-
     if conf[CONF_TYPE] == FRAMEWORK_ESP_IDF:
-        cg.add_platformio_option("framework", "espidf")
         cg.add_build_flag("-DUSE_ESP_IDF")
         cg.add_build_flag("-DUSE_ESP32_FRAMEWORK_ESP_IDF")
+        if use_platformio:
+            cg.add_platformio_option("framework", "espidf")
     else:
-        cg.add_platformio_option("framework", "arduino, espidf")
         cg.add_build_flag("-DUSE_ARDUINO")
         cg.add_build_flag("-DUSE_ESP32_FRAMEWORK_ARDUINO")
+        if use_platformio:
+            cg.add_platformio_option("framework", "arduino, espidf")
+
+            # Add IDF framework source for Arduino builds to ensure it uses the same version as
+            # the ESP-IDF framework
+            if (idf_ver := ARDUINO_IDF_VERSION_LOOKUP.get(framework_ver)) is not None:
+                cg.add_platformio_option(
+                    "platform_packages",
+                    [_format_framework_espidf_version(idf_ver, None)],
+                )
+
+            # ESP32-S2 Arduino: Disable USB Serial on boot to avoid TinyUSB dependency
+            if get_esp32_variant() == VARIANT_ESP32S2:
+                cg.add_build_unflag("-DARDUINO_USB_CDC_ON_BOOT=1")
+                cg.add_build_unflag("-DARDUINO_USB_CDC_ON_BOOT=0")
+                cg.add_build_flag("-DARDUINO_USB_CDC_ON_BOOT=0")
+
         cg.add_define(
             "USE_ARDUINO_VERSION_CODE",
             cg.RawExpression(
                 f"VERSION_CODE({framework_ver.major}, {framework_ver.minor}, {framework_ver.patch})"
             ),
         )
+
         add_idf_sdkconfig_option("CONFIG_MBEDTLS_PSK_MODES", True)
         add_idf_sdkconfig_option("CONFIG_MBEDTLS_CERTIFICATE_BUNDLE", True)
 
-        # Add IDF framework source for Arduino builds to ensure it uses the same version as
-        # the ESP-IDF framework
-        if (idf_ver := ARDUINO_IDF_VERSION_LOOKUP.get(framework_ver)) is not None:
-            cg.add_platformio_option(
-                "platform_packages", [_format_framework_espidf_version(idf_ver, None)]
-            )
-
-        # ESP32-S2 Arduino: Disable USB Serial on boot to avoid TinyUSB dependency
-        if get_esp32_variant() == VARIANT_ESP32S2:
-            cg.add_build_unflag("-DARDUINO_USB_CDC_ON_BOOT=1")
-            cg.add_build_unflag("-DARDUINO_USB_CDC_ON_BOOT=0")
-            cg.add_build_flag("-DARDUINO_USB_CDC_ON_BOOT=0")
-
     cg.add_build_flag("-Wno-nonnull-compare")
 
     add_idf_sdkconfig_option(f"CONFIG_IDF_TARGET_{variant}", True)
@@ -1196,7 +1224,8 @@ async def to_code(config):
             "CONFIG_VFS_SUPPORT_DIR", not advanced[CONF_DISABLE_VFS_SUPPORT_DIR]
         )
 
-    cg.add_platformio_option("board_build.partitions", "partitions.csv")
+    if use_platformio:
+        cg.add_platformio_option("board_build.partitions", "partitions.csv")
     if CONF_PARTITIONS in config:
         add_extra_build_file(
             "partitions.csv", CORE.relative_config_path(config[CONF_PARTITIONS])
@@ -1361,19 +1390,16 @@ def copy_files():
     _write_idf_component_yml()
 
     if "partitions.csv" not in CORE.data[KEY_ESP32][KEY_EXTRA_BUILD_FILES]:
+        flash_size = CORE.data[KEY_ESP32][KEY_FLASH_SIZE]
         if CORE.using_arduino:
             write_file_if_changed(
                 CORE.relative_build_path("partitions.csv"),
-                get_arduino_partition_csv(
-                    CORE.platformio_options.get("board_upload.flash_size")
-                ),
+                get_arduino_partition_csv(flash_size),
             )
         else:
             write_file_if_changed(
                 CORE.relative_build_path("partitions.csv"),
-                get_idf_partition_csv(
-                    CORE.platformio_options.get("board_upload.flash_size")
-                ),
+                get_idf_partition_csv(flash_size),
             )
     # IDF build scripts look for version string to put in the build.
     # However, if the build path does not have an initialized git repo,
diff --git a/esphome/components/esp32/const.py b/esphome/components/esp32/const.py
index dfb736f615..2a9456db23 100644
--- a/esphome/components/esp32/const.py
+++ b/esphome/components/esp32/const.py
@@ -2,6 +2,7 @@ import esphome.codegen as cg
 
 KEY_ESP32 = "esp32"
 KEY_BOARD = "board"
+KEY_FLASH_SIZE = "flash_size"
 KEY_VARIANT = "variant"
 KEY_SDKCONFIG_OPTIONS = "sdkconfig_options"
 KEY_COMPONENTS = "components"
diff --git a/esphome/components/esp32/preferences.cpp b/esphome/components/esp32/preferences.cpp
index 08439746b6..4e0bb68133 100644
--- a/esphome/components/esp32/preferences.cpp
+++ b/esphome/components/esp32/preferences.cpp
@@ -181,7 +181,8 @@ class ESP32Preferences : public ESPPreferences {
     if (actual_len != to_save.len) {
       return true;
     }
-    auto stored_data = std::make_unique<uint8_t[]>(actual_len);
+    // Most preferences are small, use stack buffer with heap fallback for large ones
+    SmallBufferWithHeapFallback<256> stored_data(actual_len);
     err = nvs_get_blob(nvs_handle, key_str, stored_data.get(), &actual_len);
     if (err != 0) {
       ESP_LOGV(TAG, "nvs_get_blob('%s') failed: %s", key_str, esp_err_to_name(err));
diff --git a/esphome/components/esp32_ble/ble_uuid.h b/esphome/components/esp32_ble/ble_uuid.h
index ae593955a4..6c8ef7bfd9 100644
--- a/esphome/components/esp32_ble/ble_uuid.h
+++ b/esphome/components/esp32_ble/ble_uuid.h
@@ -46,6 +46,8 @@ class ESPBTUUID {
 
   esp_bt_uuid_t get_uuid() const;
 
+  // Remove before 2026.8.0
+  ESPDEPRECATED("Use to_str() instead. Removed in 2026.8.0", "2026.2.0")
   std::string to_string() const;
   const char *to_str(std::span<char, UUID_STR_LEN> output) const;
 
diff --git a/esphome/components/esp32_ble_client/ble_client_base.cpp b/esphome/components/esp32_ble_client/ble_client_base.cpp
index 01f79156a9..c464c89390 100644
--- a/esphome/components/esp32_ble_client/ble_client_base.cpp
+++ b/esphome/components/esp32_ble_client/ble_client_base.cpp
@@ -50,7 +50,7 @@ void BLEClientBase::loop() {
     this->set_state(espbt::ClientState::INIT);
     return;
   }
-  if (this->state_ == espbt::ClientState::INIT) {
+  if (this->state() == espbt::ClientState::INIT) {
     auto ret = esp_ble_gattc_app_register(this->app_id);
     if (ret) {
       ESP_LOGE(TAG, "gattc app register failed. app_id=%d code=%d", this->app_id, ret);
@@ -60,7 +60,7 @@ void BLEClientBase::loop() {
   }
   // If idle, we can disable the loop as connect()
   // will enable it again when a connection is needed.
-  else if (this->state_ == espbt::ClientState::IDLE) {
+  else if (this->state() == espbt::ClientState::IDLE) {
     this->disable_loop();
   }
 }
@@ -86,7 +86,7 @@ bool BLEClientBase::parse_device(const espbt::ESPBTDevice &device) {
     return false;
   if (this->address_ == 0 || device.address_uint64() != this->address_)
     return false;
-  if (this->state_ != espbt::ClientState::IDLE)
+  if (this->state() != espbt::ClientState::IDLE)
     return false;
 
   this->log_event_("Found device");
@@ -102,10 +102,10 @@ bool BLEClientBase::parse_device(const espbt::ESPBTDevice &device) {
 
 void BLEClientBase::connect() {
   // Prevent duplicate connection attempts
-  if (this->state_ == espbt::ClientState::CONNECTING || this->state_ == espbt::ClientState::CONNECTED ||
-      this->state_ == espbt::ClientState::ESTABLISHED) {
+  if (this->state() == espbt::ClientState::CONNECTING || this->state() == espbt::ClientState::CONNECTED ||
+      this->state() == espbt::ClientState::ESTABLISHED) {
     ESP_LOGW(TAG, "[%d] [%s] Connection already in progress, state=%s", this->connection_index_, this->address_str_,
-             espbt::client_state_to_string(this->state_));
+             espbt::client_state_to_string(this->state()));
     return;
   }
   ESP_LOGI(TAG, "[%d] [%s] 0x%02x Connecting", this->connection_index_, this->address_str_, this->remote_addr_type_);
@@ -133,12 +133,12 @@ void BLEClientBase::connect() {
 esp_err_t BLEClientBase::pair() { return esp_ble_set_encryption(this->remote_bda_, ESP_BLE_SEC_ENCRYPT); }
 
 void BLEClientBase::disconnect() {
-  if (this->state_ == espbt::ClientState::IDLE || this->state_ == espbt::ClientState::DISCONNECTING) {
+  if (this->state() == espbt::ClientState::IDLE || this->state() == espbt::ClientState::DISCONNECTING) {
     ESP_LOGI(TAG, "[%d] [%s] Disconnect requested, but already %s", this->connection_index_, this->address_str_,
-             espbt::client_state_to_string(this->state_));
+             espbt::client_state_to_string(this->state()));
     return;
   }
-  if (this->state_ == espbt::ClientState::CONNECTING || this->conn_id_ == UNSET_CONN_ID) {
+  if (this->state() == espbt::ClientState::CONNECTING || this->conn_id_ == UNSET_CONN_ID) {
     ESP_LOGD(TAG, "[%d] [%s] Disconnect before connected, disconnect scheduled", this->connection_index_,
              this->address_str_);
     this->want_disconnect_ = true;
@@ -150,7 +150,7 @@ void BLEClientBase::disconnect() {
 void BLEClientBase::unconditional_disconnect() {
   // Disconnect without checking the state.
   ESP_LOGI(TAG, "[%d] [%s] Disconnecting (conn_id: %d).", this->connection_index_, this->address_str_, this->conn_id_);
-  if (this->state_ == espbt::ClientState::DISCONNECTING) {
+  if (this->state() == espbt::ClientState::DISCONNECTING) {
     this->log_error_("Already disconnecting");
     return;
   }
@@ -170,7 +170,7 @@ void BLEClientBase::unconditional_disconnect() {
     this->log_gattc_warning_("esp_ble_gattc_close", err);
   }
 
-  if (this->state_ == espbt::ClientState::DISCOVERED) {
+  if (this->state() == espbt::ClientState::DISCOVERED) {
     this->set_address(0);
     this->set_state(espbt::ClientState::IDLE);
   } else {
@@ -295,18 +295,18 @@ bool BLEClientBase::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_
       // ESP-IDF's BLE stack may send ESP_GATTC_OPEN_EVT after esp_ble_gattc_open() returns an
       // error, if the error occurred at the BTA/GATT layer. This can result in the event
       // arriving after we've already transitioned to IDLE state.
-      if (this->state_ == espbt::ClientState::IDLE) {
+      if (this->state() == espbt::ClientState::IDLE) {
         ESP_LOGD(TAG, "[%d] [%s] ESP_GATTC_OPEN_EVT in IDLE state (status=%d), ignoring", this->connection_index_,
                  this->address_str_, param->open.status);
         break;
       }
 
-      if (this->state_ != espbt::ClientState::CONNECTING) {
+      if (this->state() != espbt::ClientState::CONNECTING) {
         // This should not happen but lets log it in case it does
         // because it means we have a bad assumption about how the
         // ESP BT stack works.
         ESP_LOGE(TAG, "[%d] [%s] ESP_GATTC_OPEN_EVT in %s state (status=%d)", this->connection_index_,
-                 this->address_str_, espbt::client_state_to_string(this->state_), param->open.status);
+                 this->address_str_, espbt::client_state_to_string(this->state()), param->open.status);
       }
       if (param->open.status != ESP_GATT_OK && param->open.status != ESP_GATT_ALREADY_OPEN) {
         this->log_gattc_warning_("Connection open", param->open.status);
@@ -327,7 +327,7 @@ bool BLEClientBase::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_
       if (this->connection_type_ == espbt::ConnectionType::V3_WITH_CACHE) {
         // Cached connections already connected with medium parameters, no update needed
         // only set our state, subclients might have more stuff to do yet.
-        this->state_ = espbt::ClientState::ESTABLISHED;
+        this->set_state_internal_(espbt::ClientState::ESTABLISHED);
         break;
       }
       // For V3_WITHOUT_CACHE, we already set fast params before connecting
@@ -356,7 +356,7 @@ bool BLEClientBase::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_
         return false;
       // Check if we were disconnected while waiting for service discovery
       if (param->disconnect.reason == ESP_GATT_CONN_TERMINATE_PEER_USER &&
-          this->state_ == espbt::ClientState::CONNECTED) {
+          this->state() == espbt::ClientState::CONNECTED) {
         this->log_warning_("Remote closed during discovery");
       } else {
         ESP_LOGD(TAG, "[%d] [%s] ESP_GATTC_DISCONNECT_EVT, reason 0x%02x", this->connection_index_, this->address_str_,
@@ -433,7 +433,7 @@ bool BLEClientBase::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_
 #endif
       }
       ESP_LOGI(TAG, "[%d] [%s] Service discovery complete", this->connection_index_, this->address_str_);
-      this->state_ = espbt::ClientState::ESTABLISHED;
+      this->set_state_internal_(espbt::ClientState::ESTABLISHED);
       break;
     }
     case ESP_GATTC_READ_DESCR_EVT: {
diff --git a/esphome/components/esp32_ble_client/ble_client_base.h b/esphome/components/esp32_ble_client/ble_client_base.h
index c52f0e5d2d..c2336b2349 100644
--- a/esphome/components/esp32_ble_client/ble_client_base.h
+++ b/esphome/components/esp32_ble_client/ble_client_base.h
@@ -44,7 +44,7 @@ class BLEClientBase : public espbt::ESPBTClient, public Component {
   void unconditional_disconnect();
   void release_services();
 
-  bool connected() { return this->state_ == espbt::ClientState::ESTABLISHED; }
+  bool connected() { return this->state() == espbt::ClientState::ESTABLISHED; }
 
   void set_auto_connect(bool auto_connect) { this->auto_connect_ = auto_connect; }
 
diff --git a/esphome/components/esp32_ble_tracker/esp32_ble_tracker.cpp b/esphome/components/esp32_ble_tracker/esp32_ble_tracker.cpp
index 995755ac84..73a298d279 100644
--- a/esphome/components/esp32_ble_tracker/esp32_ble_tracker.cpp
+++ b/esphome/components/esp32_ble_tracker/esp32_ble_tracker.cpp
@@ -105,15 +105,13 @@ void ESP32BLETracker::loop() {
   }
 
   // Check for scan timeout - moved here from scheduler to avoid false reboots
-  // when the loop is blocked
+  // when the loop is blocked. This must run every iteration for safety.
   if (this->scanner_state_ == ScannerState::RUNNING) {
     switch (this->scan_timeout_state_) {
       case ScanTimeoutState::MONITORING: {
-        uint32_t now = App.get_loop_component_start_time();
-        uint32_t timeout_ms = this->scan_duration_ * 2000;
         // Robust time comparison that handles rollover correctly
         // This works because unsigned arithmetic wraps around predictably
-        if ((now - this->scan_start_time_) > timeout_ms) {
+        if ((App.get_loop_component_start_time() - this->scan_start_time_) > this->scan_timeout_ms_) {
           // First time we've seen the timeout exceeded - wait one more loop iteration
           // This ensures all components have had a chance to process pending events
           // This is because esp32_ble may not have run yet and called
@@ -128,13 +126,31 @@ void ESP32BLETracker::loop() {
         ESP_LOGE(TAG, "Scan never terminated, rebooting");
         App.reboot();
         break;
-
       case ScanTimeoutState::INACTIVE:
-        // This case should be unreachable - scanner and timeout states are always synchronized
         break;
     }
   }
 
+  // Fast path: skip expensive client state counting and processing
+  // if no state has changed since last loop iteration.
+  //
+  // How state changes ensure we reach the code below:
+  // - handle_scanner_failure_(): scanner_state_ becomes FAILED via set_scanner_state_(), or
+  //   scan_set_param_failed_ requires scanner_state_==RUNNING which can only be reached via
+  //   set_scanner_state_(RUNNING) in gap_scan_start_complete_() (scan params are set during
+  //   STARTING, not RUNNING, so version is always incremented before this condition is true)
+  // - start_scan_(): scanner_state_ becomes IDLE via set_scanner_state_() in cleanup_scan_state_()
+  // - try_promote_discovered_clients_(): client enters DISCOVERED via set_state(), or
+  //   connecting client finishes (state change), or scanner reaches RUNNING/IDLE
+  //
+  // All conditions that affect the logic below are tied to state changes that increment
+  // state_version_, so the fast path is safe.
+  if (this->state_version_ == this->last_processed_version_) {
+    return;
+  }
+  this->last_processed_version_ = this->state_version_;
+
+  // State changed - do full processing
   ClientStateCounts counts = this->count_client_states_();
   if (counts != this->client_state_counts_) {
     this->client_state_counts_ = counts;
@@ -142,6 +158,7 @@ void ESP32BLETracker::loop() {
              this->client_state_counts_.discovered, this->client_state_counts_.disconnecting);
   }
 
+  // Scanner failure: reached when set_scanner_state_(FAILED) or scan_set_param_failed_ set
   if (this->scanner_state_ == ScannerState::FAILED ||
       (this->scan_set_param_failed_ && this->scanner_state_ == ScannerState::RUNNING)) {
     this->handle_scanner_failure_();
@@ -160,6 +177,8 @@ void ESP32BLETracker::loop() {
 
   */
 
+  // Start scan: reached when scanner_state_ becomes IDLE (via set_scanner_state_()) and
+  // all clients are idle (their state changes increment version when they finish)
   if (this->scanner_state_ == ScannerState::IDLE && !counts.connecting && !counts.disconnecting && !counts.discovered) {
 #ifdef USE_ESP32_BLE_SOFTWARE_COEXISTENCE
     this->update_coex_preference_(false);
@@ -168,8 +187,9 @@ void ESP32BLETracker::loop() {
       this->start_scan_(false);  // first = false
     }
   }
-  // If there is a discovered client and no connecting
-  // clients, then promote the discovered client to ready to connect.
+  // Promote discovered clients: reached when a client's state becomes DISCOVERED (via set_state()),
+  // or when a blocking condition clears (connecting client finishes, scanner reaches RUNNING/IDLE).
+  // All these trigger state_version_ increment, so we'll process and check promotion eligibility.
   // We check both RUNNING and IDLE states because:
   // - RUNNING: gap_scan_event_handler initiates stop_scan_() but promotion can happen immediately
   // - IDLE: Scanner has already stopped (naturally or by gap_scan_event_handler)
@@ -236,6 +256,7 @@ void ESP32BLETracker::start_scan_(bool first) {
   // Start timeout monitoring in loop() instead of using scheduler
   // This prevents false reboots when the loop is blocked
   this->scan_start_time_ = App.get_loop_component_start_time();
+  this->scan_timeout_ms_ = this->scan_duration_ * 2000;
   this->scan_timeout_state_ = ScanTimeoutState::MONITORING;
 
   esp_err_t err = esp_ble_gap_set_scan_params(&this->scan_params_);
@@ -253,6 +274,10 @@ void ESP32BLETracker::start_scan_(bool first) {
 void ESP32BLETracker::register_client(ESPBTClient *client) {
 #ifdef ESPHOME_ESP32_BLE_TRACKER_CLIENT_COUNT
   client->app_id = ++this->app_id_;
+  // Give client a pointer to our state_version_ so it can notify us of state changes.
+  // This enables loop() fast-path optimization - we skip expensive work when no state changed.
+  // Safe because ESP32BLETracker (singleton) outlives all registered clients.
+  client->set_tracker_state_version(&this->state_version_);
   this->clients_.push_back(client);
   this->recalculate_advertisement_parser_types();
 #endif
@@ -382,6 +407,7 @@ void ESP32BLETracker::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_i
 
 void ESP32BLETracker::set_scanner_state_(ScannerState state) {
   this->scanner_state_ = state;
+  this->state_version_++;
   for (auto *listener : this->scanner_state_listeners_) {
     listener->on_scanner_state(state);
   }
diff --git a/esphome/components/esp32_ble_tracker/esp32_ble_tracker.h b/esphome/components/esp32_ble_tracker/esp32_ble_tracker.h
index f538a0eddc..fa0cdb6f45 100644
--- a/esphome/components/esp32_ble_tracker/esp32_ble_tracker.h
+++ b/esphome/components/esp32_ble_tracker/esp32_ble_tracker.h
@@ -216,6 +216,19 @@ enum class ConnectionType : uint8_t {
   V3_WITHOUT_CACHE
 };
 
+/// Base class for BLE GATT clients that connect to remote devices.
+///
+/// State Change Tracking Design:
+/// -----------------------------
+/// ESP32BLETracker::loop() needs to know when client states change to avoid
+/// expensive polling. Rather than checking all clients every iteration (~7000/min),
+/// we use a version counter owned by ESP32BLETracker that clients increment on
+/// state changes. The tracker compares versions to skip work when nothing changed.
+///
+/// Ownership: ESP32BLETracker owns state_version_. Clients hold a non-owning
+/// pointer (tracker_state_version_) set during register_client(). Clients
+/// increment the counter through this pointer when their state changes.
+/// The pointer may be null if the client is not registered with a tracker.
 class ESPBTClient : public ESPBTDeviceListener {
  public:
   virtual bool gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if,
@@ -225,26 +238,49 @@ class ESPBTClient : public ESPBTDeviceListener {
   virtual void disconnect() = 0;
   bool disconnect_pending() const { return this->want_disconnect_; }
   void cancel_pending_disconnect() { this->want_disconnect_ = false; }
+
+  /// Set the client state with IDLE handling (clears want_disconnect_).
+  /// Notifies the tracker of state change for loop optimization.
   virtual void set_state(ClientState st) {
-    this->state_ = st;
+    this->set_state_internal_(st);
     if (st == ClientState::IDLE) {
       this->want_disconnect_ = false;
     }
   }
-  ClientState state() const { return state_; }
+  ClientState state() const { return this->state_; }
+
+  /// Called by ESP32BLETracker::register_client() to enable state change notifications.
+  /// The pointer must remain valid for the lifetime of the client (guaranteed since
+  /// ESP32BLETracker is a singleton that outlives all clients).
+  void set_tracker_state_version(uint8_t *version) { this->tracker_state_version_ = version; }
 
   // Memory optimized layout
   uint8_t app_id;  // App IDs are small integers assigned sequentially
 
  protected:
-  // Group 1: 1-byte types
-  ClientState state_{ClientState::INIT};
+  /// Set state without IDLE handling - use for direct state transitions.
+  /// Increments the tracker's state version counter to signal that loop()
+  /// should do full processing on the next iteration.
+  void set_state_internal_(ClientState st) {
+    this->state_ = st;
+    // Notify tracker that state changed (tracker_state_version_ is owned by ESP32BLETracker)
+    if (this->tracker_state_version_ != nullptr) {
+      (*this->tracker_state_version_)++;
+    }
+  }
+
   // want_disconnect_ is set to true when a disconnect is requested
   // while the client is connecting. This is used to disconnect the
   // client as soon as we get the connection id (conn_id_) from the
   // ESP_GATTC_OPEN_EVT event.
   bool want_disconnect_{false};
-  // 2 bytes used, 2 bytes padding
+
+ private:
+  ClientState state_{ClientState::INIT};
+  /// Non-owning pointer to ESP32BLETracker::state_version_. When this client's
+  /// state changes, we increment the tracker's counter to signal that loop()
+  /// should perform full processing. Null if client not registered with tracker.
+  uint8_t *tracker_state_version_{nullptr};
 };
 
 class ESP32BLETracker : public Component,
@@ -380,6 +416,16 @@ class ESP32BLETracker : public Component,
   // Group 4: 1-byte types (enums, uint8_t, bool)
   uint8_t app_id_{0};
   uint8_t scan_start_fail_count_{0};
+  /// Version counter for loop() fast-path optimization. Incremented when:
+  /// - Scanner state changes (via set_scanner_state_())
+  /// - Any registered client's state changes (clients hold pointer to this counter)
+  /// Owned by this class; clients receive non-owning pointer via register_client().
+  /// When loop() sees state_version_ == last_processed_version_, it skips expensive
+  /// client state counting and takes the fast path (just timeout check + return).
+  uint8_t state_version_{0};
+  /// Last state_version_ value when loop() did full processing. Compared against
+  /// state_version_ to detect if any state changed since last iteration.
+  uint8_t last_processed_version_{0};
   ScannerState scanner_state_{ScannerState::IDLE};
   bool scan_continuous_;
   bool scan_active_;
@@ -396,6 +442,8 @@ class ESP32BLETracker : public Component,
     EXCEEDED_WAIT,  // Timeout exceeded, waiting one loop before reboot
   };
   uint32_t scan_start_time_{0};
+  /// Precomputed timeout value: scan_duration_ * 2000
+  uint32_t scan_timeout_ms_{0};
   ScanTimeoutState scan_timeout_state_{ScanTimeoutState::INACTIVE};
 };
 
diff --git a/esphome/components/esp32_hosted/update/esp32_hosted_update.cpp b/esphome/components/esp32_hosted/update/esp32_hosted_update.cpp
index d69a438578..ebcdd5f36e 100644
--- a/esphome/components/esp32_hosted/update/esp32_hosted_update.cpp
+++ b/esphome/components/esp32_hosted/update/esp32_hosted_update.cpp
@@ -11,6 +11,7 @@
 #include <esp_ota_ops.h>
 
 #ifdef USE_ESP32_HOSTED_HTTP_UPDATE
+#include "esphome/components/http_request/http_request.h"
 #include "esphome/components/json/json_util.h"
 #include "esphome/components/network/util.h"
 #endif
@@ -69,7 +70,10 @@ void Esp32HostedUpdate::setup() {
   // Get coprocessor version
   esp_hosted_coprocessor_fwver_t ver_info;
   if (esp_hosted_get_coprocessor_fwversion(&ver_info) == ESP_OK) {
-    this->update_info_.current_version = str_sprintf("%d.%d.%d", ver_info.major1, ver_info.minor1, ver_info.patch1);
+    // 16 bytes: "255.255.255" (11 chars) + null + safety margin
+    char buf[16];
+    snprintf(buf, sizeof(buf), "%d.%d.%d", ver_info.major1, ver_info.minor1, ver_info.patch1);
+    this->update_info_.current_version = buf;
   } else {
     this->update_info_.current_version = "unknown";
   }
@@ -181,15 +185,23 @@ bool Esp32HostedUpdate::fetch_manifest_() {
   }
 
   // Read manifest JSON into string (manifest is small, ~1KB max)
+  // NOTE: HttpContainer::read() has non-BSD socket semantics - see http_request.h
+  // Use http_read_loop_result() helper instead of checking return values directly
   std::string json_str;
   json_str.reserve(container->content_length);
   uint8_t buf[256];
+  uint32_t last_data_time = millis();
+  const uint32_t read_timeout = this->http_request_parent_->get_timeout();
   while (container->get_bytes_read() < container->content_length) {
-    int read = container->read(buf, sizeof(buf));
-    if (read > 0) {
-      json_str.append(reinterpret_cast<char *>(buf), read);
-    }
+    int read_or_error = container->read(buf, sizeof(buf));
+    App.feed_wdt();
     yield();
+    auto result = http_request::http_read_loop_result(read_or_error, last_data_time, read_timeout);
+    if (result == http_request::HttpReadLoopResult::RETRY)
+      continue;
+    if (result != http_request::HttpReadLoopResult::DATA)
+      break;  // ERROR or TIMEOUT
+    json_str.append(reinterpret_cast<char *>(buf), read_or_error);
   }
   container->end();
 
@@ -294,32 +306,38 @@ bool Esp32HostedUpdate::stream_firmware_to_coprocessor_() {
   }
 
   // Stream firmware to coprocessor while computing SHA256
+  // NOTE: HttpContainer::read() has non-BSD socket semantics - see http_request.h
+  // Use http_read_loop_result() helper instead of checking return values directly
   sha256::SHA256 hasher;
   hasher.init();
 
   uint8_t buffer[CHUNK_SIZE];
+  uint32_t last_data_time = millis();
+  const uint32_t read_timeout = this->http_request_parent_->get_timeout();
   while (container->get_bytes_read() < total_size) {
-    int read = container->read(buffer, sizeof(buffer));
+    int read_or_error = container->read(buffer, sizeof(buffer));
 
     // Feed watchdog and give other tasks a chance to run
     App.feed_wdt();
     yield();
 
-    // Exit loop if no data available (stream closed or end of data)
-    if (read <= 0) {
-      if (read < 0) {
-        ESP_LOGE(TAG, "Stream closed with error");
-        esp_hosted_slave_ota_end();  // NOLINT
-        container->end();
-        this->status_set_error(LOG_STR("Download failed"));
-        return false;
+    auto result = http_request::http_read_loop_result(read_or_error, last_data_time, read_timeout);
+    if (result == http_request::HttpReadLoopResult::RETRY)
+      continue;
+    if (result != http_request::HttpReadLoopResult::DATA) {
+      if (result == http_request::HttpReadLoopResult::TIMEOUT) {
+        ESP_LOGE(TAG, "Timeout reading firmware data");
+      } else {
+        ESP_LOGE(TAG, "Error reading firmware data: %d", read_or_error);
       }
-      // read == 0: no more data available, exit loop
-      break;
+      esp_hosted_slave_ota_end();  // NOLINT
+      container->end();
+      this->status_set_error(LOG_STR("Download failed"));
+      return false;
     }
 
-    hasher.add(buffer, read);
-    err = esp_hosted_slave_ota_write(buffer, read);  // NOLINT
+    hasher.add(buffer, read_or_error);
+    err = esp_hosted_slave_ota_write(buffer, read_or_error);  // NOLINT
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to write OTA data: %s", esp_err_to_name(err));
       esp_hosted_slave_ota_end();  // NOLINT
diff --git a/esphome/components/esp8266/core.cpp b/esphome/components/esp8266/core.cpp
index 200ca567c2..784b87916b 100644
--- a/esphome/components/esp8266/core.cpp
+++ b/esphome/components/esp8266/core.cpp
@@ -6,7 +6,11 @@
 #include "esphome/core/helpers.h"
 #include "preferences.h"
 #include <Arduino.h>
-#include <Esp.h>
+#include <core_esp8266_features.h>
+
+extern "C" {
+#include <user_interface.h>
+}
 
 namespace esphome {
 
@@ -16,23 +20,19 @@ void IRAM_ATTR HOT delay(uint32_t ms) { ::delay(ms); }
 uint32_t IRAM_ATTR HOT micros() { return ::micros(); }
 void IRAM_ATTR HOT delayMicroseconds(uint32_t us) { delay_microseconds_safe(us); }
 void arch_restart() {
-  ESP.restart();  // NOLINT(readability-static-accessed-through-instance)
+  system_restart();
   // restart() doesn't always end execution
   while (true) {  // NOLINT(clang-diagnostic-unreachable-code)
     yield();
   }
 }
 void arch_init() {}
-void IRAM_ATTR HOT arch_feed_wdt() {
-  ESP.wdtFeed();  // NOLINT(readability-static-accessed-through-instance)
-}
+void IRAM_ATTR HOT arch_feed_wdt() { system_soft_wdt_feed(); }
 
 uint8_t progmem_read_byte(const uint8_t *addr) {
   return pgm_read_byte(addr);  // NOLINT
 }
-uint32_t IRAM_ATTR HOT arch_get_cpu_cycle_count() {
-  return ESP.getCycleCount();  // NOLINT(readability-static-accessed-through-instance)
-}
+uint32_t IRAM_ATTR HOT arch_get_cpu_cycle_count() { return esp_get_cycle_count(); }
 uint32_t arch_get_cpu_freq_hz() { return F_CPU; }
 
 void force_link_symbols() {
diff --git a/esphome/components/esp8266/gpio.cpp b/esphome/components/esp8266/gpio.cpp
index 7a5ee08984..659233443e 100644
--- a/esphome/components/esp8266/gpio.cpp
+++ b/esphome/components/esp8266/gpio.cpp
@@ -99,7 +99,7 @@ void ESP8266GPIOPin::pin_mode(gpio::Flags flags) {
 }
 
 size_t ESP8266GPIOPin::dump_summary(char *buffer, size_t len) const {
-  return snprintf(buffer, len, "GPIO%u", this->pin_);
+  return buf_append_printf(buffer, len, 0, "GPIO%u", this->pin_);
 }
 
 bool ESP8266GPIOPin::digital_read() {
diff --git a/esphome/components/esp8266/preferences.cpp b/esphome/components/esp8266/preferences.cpp
index 47987b4a95..35d1cd07f7 100644
--- a/esphome/components/esp8266/preferences.cpp
+++ b/esphome/components/esp8266/preferences.cpp
@@ -12,7 +12,6 @@ extern "C" {
 #include "preferences.h"
 
 #include <cstring>
-#include <memory>
 
 namespace esphome::esp8266 {
 
@@ -143,16 +142,8 @@ class ESP8266PreferenceBackend : public ESPPreferenceBackend {
       return false;
 
     const size_t buffer_size = static_cast<size_t>(this->length_words) + 1;
-    uint32_t stack_buffer[PREF_BUFFER_WORDS];
-    std::unique_ptr<uint32_t[]> heap_buffer;
-    uint32_t *buffer;
-
-    if (buffer_size <= PREF_BUFFER_WORDS) {
-      buffer = stack_buffer;
-    } else {
-      heap_buffer = make_unique<uint32_t[]>(buffer_size);
-      buffer = heap_buffer.get();
-    }
+    SmallBufferWithHeapFallback<PREF_BUFFER_WORDS, uint32_t> buffer_alloc(buffer_size);
+    uint32_t *buffer = buffer_alloc.get();
     memset(buffer, 0, buffer_size * sizeof(uint32_t));
 
     memcpy(buffer, data, len);
@@ -167,16 +158,8 @@ class ESP8266PreferenceBackend : public ESPPreferenceBackend {
       return false;
 
     const size_t buffer_size = static_cast<size_t>(this->length_words) + 1;
-    uint32_t stack_buffer[PREF_BUFFER_WORDS];
-    std::unique_ptr<uint32_t[]> heap_buffer;
-    uint32_t *buffer;
-
-    if (buffer_size <= PREF_BUFFER_WORDS) {
-      buffer = stack_buffer;
-    } else {
-      heap_buffer = make_unique<uint32_t[]>(buffer_size);
-      buffer = heap_buffer.get();
-    }
+    SmallBufferWithHeapFallback<PREF_BUFFER_WORDS, uint32_t> buffer_alloc(buffer_size);
+    uint32_t *buffer = buffer_alloc.get();
 
     bool ret = this->in_flash ? load_from_flash(this->offset, buffer, buffer_size)
                               : load_from_rtc(this->offset, buffer, buffer_size);
diff --git a/esphome/components/event/__init__.py b/esphome/components/event/__init__.py
index e2b69ba872..8fac7a279c 100644
--- a/esphome/components/event/__init__.py
+++ b/esphome/components/event/__init__.py
@@ -90,9 +90,7 @@ async def setup_event_core_(var, config, *, event_types: list[str]):
 
     for conf in config.get(CONF_ON_EVENT, []):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(
-            trigger, [(cg.std_string, "event_type")], conf
-        )
+        await automation.build_automation(trigger, [(cg.StringRef, "event_type")], conf)
 
     cg.add(var.set_event_types(event_types))
 
diff --git a/esphome/components/event/automation.h b/esphome/components/event/automation.h
index 5bdba18687..7730506c10 100644
--- a/esphome/components/event/automation.h
+++ b/esphome/components/event/automation.h
@@ -14,10 +14,10 @@ template<typename... Ts> class TriggerEventAction : public Action<Ts...>, public
   void play(const Ts &...x) override { this->parent_->trigger(this->event_type_.value(x...)); }
 };
 
-class EventTrigger : public Trigger<std::string> {
+class EventTrigger : public Trigger<StringRef> {
  public:
   EventTrigger(Event *event) {
-    event->add_on_event_callback([this](const std::string &event_type) { this->trigger(event_type); });
+    event->add_on_event_callback([this](StringRef event_type) { this->trigger(event_type); });
   }
 };
 
diff --git a/esphome/components/event/event.cpp b/esphome/components/event/event.cpp
index 8015f2255a..667d4218f3 100644
--- a/esphome/components/event/event.cpp
+++ b/esphome/components/event/event.cpp
@@ -23,7 +23,7 @@ void Event::trigger(const std::string &event_type) {
   }
   this->last_event_type_ = found;
   ESP_LOGD(TAG, "'%s' >> '%s'", this->get_name().c_str(), this->last_event_type_);
-  this->event_callback_.call(event_type);
+  this->event_callback_.call(StringRef(found));
 #if defined(USE_EVENT) && defined(USE_CONTROLLER_REGISTRY)
   ControllerRegistry::notify_event(this);
 #endif
@@ -45,7 +45,7 @@ void Event::set_event_types(const std::vector<const char *> &event_types) {
   this->last_event_type_ = nullptr;  // Reset when types change
 }
 
-void Event::add_on_event_callback(std::function<void(const std::string &event_type)> &&callback) {
+void Event::add_on_event_callback(std::function<void(StringRef event_type)> &&callback) {
   this->event_callback_.add(std::move(callback));
 }
 
diff --git a/esphome/components/event/event.h b/esphome/components/event/event.h
index f77ad326d9..b5519a0520 100644
--- a/esphome/components/event/event.h
+++ b/esphome/components/event/event.h
@@ -70,10 +70,10 @@ class Event : public EntityBase, public EntityBase_DeviceClass {
   /// Check if an event has been triggered.
   bool has_event() const { return this->last_event_type_ != nullptr; }
 
-  void add_on_event_callback(std::function<void(const std::string &event_type)> &&callback);
+  void add_on_event_callback(std::function<void(StringRef event_type)> &&callback);
 
  protected:
-  LazyCallbackManager<void(const std::string &event_type)> event_callback_;
+  LazyCallbackManager<void(StringRef event_type)> event_callback_;
   FixedVector<const char *> types_;
 
  private:
diff --git a/esphome/components/ezo/ezo.cpp b/esphome/components/ezo/ezo.cpp
index 2e92c58e29..e4036021df 100644
--- a/esphome/components/ezo/ezo.cpp
+++ b/esphome/components/ezo/ezo.cpp
@@ -160,7 +160,7 @@ void EZOSensor::loop() {
   this->commands_.pop_front();
 }
 
-void EZOSensor::add_command_(const std::string &command, EzoCommandType command_type, uint16_t delay_ms) {
+void EZOSensor::add_command_(const char *command, EzoCommandType command_type, uint16_t delay_ms) {
   std::unique_ptr<EzoCommand> ezo_command(new EzoCommand);
   ezo_command->command = command;
   ezo_command->command_type = command_type;
@@ -169,13 +169,17 @@ void EZOSensor::add_command_(const std::string &command, EzoCommandType command_
 }
 
 void EZOSensor::set_calibration_point_(EzoCalibrationType type, float value) {
-  std::string payload = str_sprintf("Cal,%s,%0.2f", EZO_CALIBRATION_TYPE_STRINGS[type], value);
+  // max 21: "Cal,"(4) + type(4) + ","(1) + float(11) + null; use 24 for safety
+  char payload[24];
+  snprintf(payload, sizeof(payload), "Cal,%s,%0.2f", EZO_CALIBRATION_TYPE_STRINGS[type], value);
   this->add_command_(payload, EzoCommandType::EZO_CALIBRATION, 900);
 }
 
 void EZOSensor::set_address(uint8_t address) {
   if (address > 0 && address < 128) {
-    std::string payload = str_sprintf("I2C,%u", address);
+    // max 8: "I2C,"(4) + uint8(3) + null
+    char payload[8];
+    snprintf(payload, sizeof(payload), "I2C,%u", address);
     this->new_address_ = address;
     this->add_command_(payload, EzoCommandType::EZO_I2C);
   } else {
@@ -194,7 +198,9 @@ void EZOSensor::get_slope() { this->add_command_("Slope,?", EzoCommandType::EZO_
 void EZOSensor::get_t() { this->add_command_("T,?", EzoCommandType::EZO_T); }
 
 void EZOSensor::set_t(float value) {
-  std::string payload = str_sprintf("T,%0.2f", value);
+  // max 14 bytes: "T,"(2) + float with "%0.2f" (up to 11 chars) + null(1); use 16 for alignment
+  char payload[16];
+  snprintf(payload, sizeof(payload), "T,%0.2f", value);
   this->add_command_(payload, EzoCommandType::EZO_T);
 }
 
@@ -215,7 +221,9 @@ void EZOSensor::set_calibration_point_high(float value) {
 }
 
 void EZOSensor::set_calibration_generic(float value) {
-  std::string payload = str_sprintf("Cal,%0.2f", value);
+  // exact 16 bytes: "Cal," (4) + float with "%0.2f" (up to 11 chars, e.g. "-9999999.99") + null (1) = 16
+  char payload[16];
+  snprintf(payload, sizeof(payload), "Cal,%0.2f", value);
   this->add_command_(payload, EzoCommandType::EZO_CALIBRATION, 900);
 }
 
@@ -223,13 +231,11 @@ void EZOSensor::clear_calibration() { this->add_command_("Cal,clear", EzoCommand
 
 void EZOSensor::get_led_state() { this->add_command_("L,?", EzoCommandType::EZO_LED); }
 
-void EZOSensor::set_led_state(bool on) {
-  std::string to_send = "L,";
-  to_send += on ? "1" : "0";
-  this->add_command_(to_send, EzoCommandType::EZO_LED);
-}
+void EZOSensor::set_led_state(bool on) { this->add_command_(on ? "L,1" : "L,0", EzoCommandType::EZO_LED); }
 
-void EZOSensor::send_custom(const std::string &to_send) { this->add_command_(to_send, EzoCommandType::EZO_CUSTOM); }
+void EZOSensor::send_custom(const std::string &to_send) {
+  this->add_command_(to_send.c_str(), EzoCommandType::EZO_CUSTOM);
+}
 
 }  // namespace ezo
 }  // namespace esphome
diff --git a/esphome/components/ezo/ezo.h b/esphome/components/ezo/ezo.h
index 00dd98fc80..f1a2802cbd 100644
--- a/esphome/components/ezo/ezo.h
+++ b/esphome/components/ezo/ezo.h
@@ -92,7 +92,7 @@ class EZOSensor : public sensor::Sensor, public PollingComponent, public i2c::I2
   std::deque<std::unique_ptr<EzoCommand>> commands_;
   int new_address_;
 
-  void add_command_(const std::string &command, EzoCommandType command_type, uint16_t delay_ms = 300);
+  void add_command_(const char *command, EzoCommandType command_type, uint16_t delay_ms = 300);
 
   void set_calibration_point_(EzoCalibrationType type, float value);
 
diff --git a/esphome/components/ezo_pmp/ezo_pmp.cpp b/esphome/components/ezo_pmp/ezo_pmp.cpp
index 61b601328a..9d2f4fc687 100644
--- a/esphome/components/ezo_pmp/ezo_pmp.cpp
+++ b/esphome/components/ezo_pmp/ezo_pmp.cpp
@@ -318,90 +318,93 @@ void EzoPMP::send_next_command_() {
   switch (this->next_command_) {
     // Read Commands
     case EZO_PMP_COMMAND_READ_DOSING:  // Page 54
-      command_buffer_length = sprintf((char *) command_buffer, "D,?");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "D,?");
       break;
 
     case EZO_PMP_COMMAND_READ_SINGLE_REPORT:  // Single Report (page 53)
-      command_buffer_length = sprintf((char *) command_buffer, "R");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "R");
       break;
 
     case EZO_PMP_COMMAND_READ_MAX_FLOW_RATE:
-      command_buffer_length = sprintf((char *) command_buffer, "DC,?");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "DC,?");
       break;
 
     case EZO_PMP_COMMAND_READ_PAUSE_STATUS:
-      command_buffer_length = sprintf((char *) command_buffer, "P,?");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "P,?");
       break;
 
     case EZO_PMP_COMMAND_READ_TOTAL_VOLUME_DOSED:
-      command_buffer_length = sprintf((char *) command_buffer, "TV,?");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "TV,?");
       break;
 
     case EZO_PMP_COMMAND_READ_ABSOLUTE_TOTAL_VOLUME_DOSED:
-      command_buffer_length = sprintf((char *) command_buffer, "ATV,?");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "ATV,?");
       break;
 
     case EZO_PMP_COMMAND_READ_CALIBRATION_STATUS:
-      command_buffer_length = sprintf((char *) command_buffer, "Cal,?");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "Cal,?");
       break;
 
     case EZO_PMP_COMMAND_READ_PUMP_VOLTAGE:
-      command_buffer_length = sprintf((char *) command_buffer, "PV,?");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "PV,?");
       break;
 
       // Non-Read Commands
 
     case EZO_PMP_COMMAND_FIND:  // Find (page 52)
-      command_buffer_length = sprintf((char *) command_buffer, "Find");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "Find");
       wait_time_for_command = 60000;  // This command will block all updates for a minute
       break;
 
     case EZO_PMP_COMMAND_DOSE_CONTINUOUSLY:  // Continuous Dispensing (page 54)
-      command_buffer_length = sprintf((char *) command_buffer, "D,*");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "D,*");
       break;
 
     case EZO_PMP_COMMAND_CLEAR_TOTAL_VOLUME_DOSED:  // Clear Total Volume Dosed (page 64)
-      command_buffer_length = sprintf((char *) command_buffer, "Clear");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "Clear");
       break;
 
     case EZO_PMP_COMMAND_CLEAR_CALIBRATION:  // Clear Calibration (page 65)
-      command_buffer_length = sprintf((char *) command_buffer, "Cal,clear");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "Cal,clear");
       break;
 
     case EZO_PMP_COMMAND_PAUSE_DOSING:  // Pause (page 61)
-      command_buffer_length = sprintf((char *) command_buffer, "P");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "P");
       break;
 
     case EZO_PMP_COMMAND_STOP_DOSING:  // Stop (page 62)
-      command_buffer_length = sprintf((char *) command_buffer, "X");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "X");
       break;
 
       // Non-Read commands with parameters
 
     case EZO_PMP_COMMAND_DOSE_VOLUME:  // Volume Dispensing (page 55)
-      command_buffer_length = sprintf((char *) command_buffer, "D,%0.1f", this->next_command_volume_);
+      command_buffer_length =
+          snprintf((char *) command_buffer, sizeof(command_buffer), "D,%0.1f", this->next_command_volume_);
       break;
 
     case EZO_PMP_COMMAND_DOSE_VOLUME_OVER_TIME:  // Dose over time (page 56)
-      command_buffer_length =
-          sprintf((char *) command_buffer, "D,%0.1f,%i", this->next_command_volume_, this->next_command_duration_);
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "D,%0.1f,%i",
+                                       this->next_command_volume_, this->next_command_duration_);
       break;
 
     case EZO_PMP_COMMAND_DOSE_WITH_CONSTANT_FLOW_RATE:  // Constant Flow Rate (page 57)
-      command_buffer_length =
-          sprintf((char *) command_buffer, "DC,%0.1f,%i", this->next_command_volume_, this->next_command_duration_);
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "DC,%0.1f,%i",
+                                       this->next_command_volume_, this->next_command_duration_);
       break;
 
     case EZO_PMP_COMMAND_SET_CALIBRATION_VOLUME:  // Set Calibration Volume (page 65)
-      command_buffer_length = sprintf((char *) command_buffer, "Cal,%0.2f", this->next_command_volume_);
+      command_buffer_length =
+          snprintf((char *) command_buffer, sizeof(command_buffer), "Cal,%0.2f", this->next_command_volume_);
       break;
 
     case EZO_PMP_COMMAND_CHANGE_I2C_ADDRESS:  // Change I2C Address (page 73)
-      command_buffer_length = sprintf((char *) command_buffer, "I2C,%i", this->next_command_duration_);
+      command_buffer_length =
+          snprintf((char *) command_buffer, sizeof(command_buffer), "I2C,%i", this->next_command_duration_);
       break;
 
     case EZO_PMP_COMMAND_EXEC_ARBITRARY_COMMAND_ADDRESS:  // Run an arbitrary command
-      command_buffer_length = sprintf((char *) command_buffer, this->arbitrary_command_, this->next_command_duration_);
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "%s", this->arbitrary_command_);
       ESP_LOGI(TAG, "Sending arbitrary command: %s", (char *) command_buffer);
       break;
 
diff --git a/esphome/components/fan/__init__.py b/esphome/components/fan/__init__.py
index 35a351e8f1..6010aa8ed4 100644
--- a/esphome/components/fan/__init__.py
+++ b/esphome/components/fan/__init__.py
@@ -77,7 +77,7 @@ FanSpeedSetTrigger = fan_ns.class_(
     "FanSpeedSetTrigger", automation.Trigger.template(cg.int_)
 )
 FanPresetSetTrigger = fan_ns.class_(
-    "FanPresetSetTrigger", automation.Trigger.template(cg.std_string)
+    "FanPresetSetTrigger", automation.Trigger.template(cg.StringRef)
 )
 
 FanIsOnCondition = fan_ns.class_("FanIsOnCondition", automation.Condition.template())
@@ -287,7 +287,7 @@ async def setup_fan_core_(var, config):
         await automation.build_automation(trigger, [(cg.int_, "x")], conf)
     for conf in config.get(CONF_ON_PRESET_SET, []):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [(cg.std_string, "x")], conf)
+        await automation.build_automation(trigger, [(cg.StringRef, "x")], conf)
 
 
 async def register_fan(var, config):
diff --git a/esphome/components/fan/automation.h b/esphome/components/fan/automation.h
index 77abc2f13f..3c3b0ce519 100644
--- a/esphome/components/fan/automation.h
+++ b/esphome/components/fan/automation.h
@@ -208,7 +208,7 @@ class FanSpeedSetTrigger : public Trigger<int> {
   int last_speed_;
 };
 
-class FanPresetSetTrigger : public Trigger<std::string> {
+class FanPresetSetTrigger : public Trigger<StringRef> {
  public:
   FanPresetSetTrigger(Fan *state) {
     state->add_on_state_callback([this, state]() {
@@ -216,7 +216,7 @@ class FanPresetSetTrigger : public Trigger<std::string> {
       auto should_trigger = preset_mode != this->last_preset_mode_;
       this->last_preset_mode_ = preset_mode;
       if (should_trigger) {
-        this->trigger(std::string(preset_mode));
+        this->trigger(preset_mode);
       }
     });
     this->last_preset_mode_ = state->get_preset_mode();
diff --git a/esphome/components/gdk101/gdk101.cpp b/esphome/components/gdk101/gdk101.cpp
index 617e2138fb..ddf38f2f55 100644
--- a/esphome/components/gdk101/gdk101.cpp
+++ b/esphome/components/gdk101/gdk101.cpp
@@ -163,9 +163,10 @@ bool GDK101Component::read_fw_version_(uint8_t *data) {
       return false;
     }
 
-    const std::string fw_version_str = str_sprintf("%d.%d", data[0], data[1]);
-
-    this->fw_version_text_sensor_->publish_state(fw_version_str);
+    // max 8: "255.255" (7 chars) + null
+    char buf[8];
+    snprintf(buf, sizeof(buf), "%d.%d", data[0], data[1]);
+    this->fw_version_text_sensor_->publish_state(buf);
   }
 #endif  // USE_TEXT_SENSOR
   return true;
diff --git a/esphome/components/hc8/sensor.py b/esphome/components/hc8/sensor.py
index 90698b2661..2f39b47f3c 100644
--- a/esphome/components/hc8/sensor.py
+++ b/esphome/components/hc8/sensor.py
@@ -6,6 +6,7 @@ from esphome.const import (
     CONF_BASELINE,
     CONF_CO2,
     CONF_ID,
+    CONF_WARMUP_TIME,
     DEVICE_CLASS_CARBON_DIOXIDE,
     ICON_MOLECULE_CO2,
     STATE_CLASS_MEASUREMENT,
@@ -14,8 +15,6 @@ from esphome.const import (
 
 DEPENDENCIES = ["uart"]
 
-CONF_WARMUP_TIME = "warmup_time"
-
 hc8_ns = cg.esphome_ns.namespace("hc8")
 HC8Component = hc8_ns.class_("HC8Component", cg.PollingComponent, uart.UARTDevice)
 HC8CalibrateAction = hc8_ns.class_("HC8CalibrateAction", automation.Action)
diff --git a/esphome/components/heatpumpir/climate.py b/esphome/components/heatpumpir/climate.py
index ec6eac670f..0d760938d0 100644
--- a/esphome/components/heatpumpir/climate.py
+++ b/esphome/components/heatpumpir/climate.py
@@ -107,7 +107,7 @@ CONFIG_SCHEMA = cv.All(
             cv.Required(CONF_MAX_TEMPERATURE): cv.temperature,
         }
     ),
-    cv.only_with_arduino,
+    cv.Any(cv.only_with_arduino, cv.only_on_esp32),
 )
 
 
@@ -126,6 +126,6 @@ async def to_code(config):
     cg.add(var.set_max_temperature(config[CONF_MAX_TEMPERATURE]))
     cg.add(var.set_min_temperature(config[CONF_MIN_TEMPERATURE]))
 
-    cg.add_library("tonia/HeatpumpIR", "1.0.37")
+    cg.add_library("tonia/HeatpumpIR", "1.0.40")
     if CORE.is_libretiny or CORE.is_esp32:
         CORE.add_platformio_option("lib_ignore", ["IRremoteESP8266"])
diff --git a/esphome/components/heatpumpir/heatpumpir.cpp b/esphome/components/heatpumpir/heatpumpir.cpp
index 67447a3123..1f1362f8d8 100644
--- a/esphome/components/heatpumpir/heatpumpir.cpp
+++ b/esphome/components/heatpumpir/heatpumpir.cpp
@@ -1,6 +1,6 @@
 #include "heatpumpir.h"
 
-#ifdef USE_ARDUINO
+#if defined(USE_ARDUINO) || defined(USE_ESP32)
 
 #include <map>
 #include "ir_sender_esphome.h"
diff --git a/esphome/components/heatpumpir/heatpumpir.h b/esphome/components/heatpumpir/heatpumpir.h
index ed43ffdc83..6270dd1e5a 100644
--- a/esphome/components/heatpumpir/heatpumpir.h
+++ b/esphome/components/heatpumpir/heatpumpir.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#ifdef USE_ARDUINO
+#if defined(USE_ARDUINO) || defined(USE_ESP32)
 
 #include "esphome/components/climate_ir/climate_ir.h"
 
diff --git a/esphome/components/heatpumpir/ir_sender_esphome.cpp b/esphome/components/heatpumpir/ir_sender_esphome.cpp
index 173d595119..f010c72dac 100644
--- a/esphome/components/heatpumpir/ir_sender_esphome.cpp
+++ b/esphome/components/heatpumpir/ir_sender_esphome.cpp
@@ -1,6 +1,6 @@
 #include "ir_sender_esphome.h"
 
-#ifdef USE_ARDUINO
+#if defined(USE_ARDUINO) || defined(USE_ESP32)
 
 namespace esphome {
 namespace heatpumpir {
diff --git a/esphome/components/heatpumpir/ir_sender_esphome.h b/esphome/components/heatpumpir/ir_sender_esphome.h
index 944d0e859c..c4209145ba 100644
--- a/esphome/components/heatpumpir/ir_sender_esphome.h
+++ b/esphome/components/heatpumpir/ir_sender_esphome.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#ifdef USE_ARDUINO
+#if defined(USE_ARDUINO) || defined(USE_ESP32)
 
 #include "esphome/components/remote_base/remote_base.h"
 #include <IRSender.h>  // arduino-heatpump library
diff --git a/esphome/components/hmac_sha256/hmac_sha256.cpp b/esphome/components/hmac_sha256/hmac_sha256.cpp
index cf5daf63af..2146e961bc 100644
--- a/esphome/components/hmac_sha256/hmac_sha256.cpp
+++ b/esphome/components/hmac_sha256/hmac_sha256.cpp
@@ -1,4 +1,3 @@
-#include <cstdio>
 #include <cstring>
 #include "hmac_sha256.h"
 #if defined(USE_ESP32) || defined(USE_ESP8266) || defined(USE_RP2040) || defined(USE_LIBRETINY) || defined(USE_HOST)
@@ -26,9 +25,7 @@ void HmacSHA256::calculate() { mbedtls_md_hmac_finish(&this->ctx_, this->digest_
 void HmacSHA256::get_bytes(uint8_t *output) { memcpy(output, this->digest_, SHA256_DIGEST_SIZE); }
 
 void HmacSHA256::get_hex(char *output) {
-  for (size_t i = 0; i < SHA256_DIGEST_SIZE; i++) {
-    sprintf(output + (i * 2), "%02x", this->digest_[i]);
-  }
+  format_hex_to(output, SHA256_DIGEST_SIZE * 2 + 1, this->digest_, SHA256_DIGEST_SIZE);
 }
 
 bool HmacSHA256::equals_bytes(const uint8_t *expected) {
diff --git a/esphome/components/homeassistant/number/homeassistant_number.cpp b/esphome/components/homeassistant/number/homeassistant_number.cpp
index 92ecd5ea39..00ea88ff16 100644
--- a/esphome/components/homeassistant/number/homeassistant_number.cpp
+++ b/esphome/components/homeassistant/number/homeassistant_number.cpp
@@ -97,7 +97,7 @@ void HomeassistantNumber::control(float value) {
   entity_value.key = VALUE_KEY;
   // Stack buffer - no heap allocation; %g produces shortest representation
   char value_buf[16];
-  snprintf(value_buf, sizeof(value_buf), "%g", value);
+  buf_append_printf(value_buf, sizeof(value_buf), 0, "%g", value);
   entity_value.value = StringRef(value_buf);
 
   api::global_api_server->send_homeassistant_action(resp);
diff --git a/esphome/components/http_request/__init__.py b/esphome/components/http_request/__init__.py
index b133aa69b2..9f74fb1023 100644
--- a/esphome/components/http_request/__init__.py
+++ b/esphome/components/http_request/__init__.py
@@ -157,6 +157,7 @@ async def to_code(config):
     if CORE.is_esp32:
         cg.add(var.set_buffer_size_rx(config[CONF_BUFFER_SIZE_RX]))
         cg.add(var.set_buffer_size_tx(config[CONF_BUFFER_SIZE_TX]))
+        cg.add(var.set_verify_ssl(config[CONF_VERIFY_SSL]))
 
         if config.get(CONF_VERIFY_SSL):
             esp32.add_idf_sdkconfig_option("CONFIG_MBEDTLS_CERTIFICATE_BUNDLE", True)
diff --git a/esphome/components/http_request/http_request.h b/esphome/components/http_request/http_request.h
index 1b5fd9f00e..fb39ca504c 100644
--- a/esphome/components/http_request/http_request.h
+++ b/esphome/components/http_request/http_request.h
@@ -79,6 +79,81 @@ inline bool is_redirect(int const status) {
  */
 inline bool is_success(int const status) { return status >= HTTP_STATUS_OK && status < HTTP_STATUS_MULTIPLE_CHOICES; }
 
+/*
+ * HTTP Container Read Semantics
+ * =============================
+ *
+ * IMPORTANT: These semantics differ from standard BSD sockets!
+ *
+ * BSD socket read() returns:
+ *   > 0: bytes read
+ *   == 0: connection closed (EOF)
+ *   < 0: error (check errno)
+ *
+ * HttpContainer::read() returns:
+ *   > 0: bytes read successfully
+ *   == 0: no data available yet OR all content read
+ *         (caller should check bytes_read vs content_length)
+ *   < 0: error or connection closed (caller should EXIT)
+ *        HTTP_ERROR_CONNECTION_CLOSED (-1) = connection closed prematurely
+ *        other negative values = platform-specific errors
+ *
+ * Platform behaviors:
+ *   - ESP-IDF: blocking reads, 0 only returned when all content read
+ *   - Arduino: non-blocking, 0 means "no data yet" or "all content read"
+ *
+ * Use the helper functions below instead of checking return values directly:
+ *   - http_read_loop_result(): for manual loops with per-chunk processing
+ *   - http_read_fully(): for simple "read N bytes into buffer" operations
+ */
+
+/// Error code returned by HttpContainer::read() when connection closed prematurely
+/// NOTE: Unlike BSD sockets where 0 means EOF, here 0 means "no data yet, retry"
+static constexpr int HTTP_ERROR_CONNECTION_CLOSED = -1;
+
+/// Status of a read operation
+enum class HttpReadStatus : uint8_t {
+  OK,       ///< Read completed successfully
+  ERROR,    ///< Read error occurred
+  TIMEOUT,  ///< Timeout waiting for data
+};
+
+/// Result of an HTTP read operation
+struct HttpReadResult {
+  HttpReadStatus status;  ///< Status of the read operation
+  int error_code;         ///< Error code from read() on failure, 0 on success
+};
+
+/// Result of processing a non-blocking read with timeout (for manual loops)
+enum class HttpReadLoopResult : uint8_t {
+  DATA,     ///< Data was read, process it
+  RETRY,    ///< No data yet, already delayed, caller should continue loop
+  ERROR,    ///< Read error, caller should exit loop
+  TIMEOUT,  ///< Timeout waiting for data, caller should exit loop
+};
+
+/// Process a read result with timeout tracking and delay handling
+/// @param bytes_read_or_error Return value from read() - positive for bytes read, negative for error
+/// @param last_data_time Time of last successful read, updated when data received
+/// @param timeout_ms Maximum time to wait for data
+/// @return DATA if data received, RETRY if should continue loop, ERROR/TIMEOUT if should exit
+inline HttpReadLoopResult http_read_loop_result(int bytes_read_or_error, uint32_t &last_data_time,
+                                                uint32_t timeout_ms) {
+  if (bytes_read_or_error > 0) {
+    last_data_time = millis();
+    return HttpReadLoopResult::DATA;
+  }
+  if (bytes_read_or_error < 0) {
+    return HttpReadLoopResult::ERROR;
+  }
+  // bytes_read_or_error == 0: no data available yet
+  if (millis() - last_data_time >= timeout_ms) {
+    return HttpReadLoopResult::TIMEOUT;
+  }
+  delay(1);  // Small delay to prevent tight spinning
+  return HttpReadLoopResult::RETRY;
+}
+
 class HttpRequestComponent;
 
 class HttpContainer : public Parented<HttpRequestComponent> {
@@ -88,6 +163,33 @@ class HttpContainer : public Parented<HttpRequestComponent> {
   int status_code;
   uint32_t duration_ms;
 
+  /**
+   * @brief Read data from the HTTP response body.
+   *
+   * WARNING: These semantics differ from BSD sockets!
+   * BSD sockets: 0 = EOF (connection closed)
+   * This method: 0 = no data yet OR all content read, negative = error/closed
+   *
+   * @param buf Buffer to read data into
+   * @param max_len Maximum number of bytes to read
+   * @return
+   *   - > 0: Number of bytes read successfully
+   *   - 0: No data available yet OR all content read
+   *        (check get_bytes_read() >= content_length to distinguish)
+   *   - HTTP_ERROR_CONNECTION_CLOSED (-1): Connection closed prematurely
+   *   - < -1: Other error (platform-specific error code)
+   *
+   * Platform notes:
+   *   - ESP-IDF: blocking read, 0 only when all content read
+   *   - Arduino: non-blocking, 0 can mean "no data yet" or "all content read"
+   *
+   * Use get_bytes_read() and content_length to track progress.
+   * When get_bytes_read() >= content_length, all data has been received.
+   *
+   * IMPORTANT: Do not use raw return values directly. Use these helpers:
+   *   - http_read_loop_result(): for loops with per-chunk processing
+   *   - http_read_fully(): for simple "read N bytes" operations
+   */
   virtual int read(uint8_t *buf, size_t max_len) = 0;
   virtual void end() = 0;
 
@@ -110,6 +212,38 @@ class HttpContainer : public Parented<HttpRequestComponent> {
   std::map<std::string, std::list<std::string>> response_headers_{};
 };
 
+/// Read data from HTTP container into buffer with timeout handling
+/// Handles feed_wdt, yield, and timeout checking internally
+/// @param container The HTTP container to read from
+/// @param buffer Buffer to read into
+/// @param total_size Total bytes to read
+/// @param chunk_size Maximum bytes per read call
+/// @param timeout_ms Read timeout in milliseconds
+/// @return HttpReadResult with status and error_code on failure
+inline HttpReadResult http_read_fully(HttpContainer *container, uint8_t *buffer, size_t total_size, size_t chunk_size,
+                                      uint32_t timeout_ms) {
+  size_t read_index = 0;
+  uint32_t last_data_time = millis();
+
+  while (read_index < total_size) {
+    int read_bytes_or_error = container->read(buffer + read_index, std::min(chunk_size, total_size - read_index));
+
+    App.feed_wdt();
+    yield();
+
+    auto result = http_read_loop_result(read_bytes_or_error, last_data_time, timeout_ms);
+    if (result == HttpReadLoopResult::RETRY)
+      continue;
+    if (result == HttpReadLoopResult::ERROR)
+      return {HttpReadStatus::ERROR, read_bytes_or_error};
+    if (result == HttpReadLoopResult::TIMEOUT)
+      return {HttpReadStatus::TIMEOUT, 0};
+
+    read_index += read_bytes_or_error;
+  }
+  return {HttpReadStatus::OK, 0};
+}
+
 class HttpRequestResponseTrigger : public Trigger<std::shared_ptr<HttpContainer>, std::string &> {
  public:
   void process(const std::shared_ptr<HttpContainer> &container, std::string &response_body) {
@@ -124,6 +258,7 @@ class HttpRequestComponent : public Component {
 
   void set_useragent(const char *useragent) { this->useragent_ = useragent; }
   void set_timeout(uint32_t timeout) { this->timeout_ = timeout; }
+  uint32_t get_timeout() const { return this->timeout_; }
   void set_watchdog_timeout(uint32_t watchdog_timeout) { this->watchdog_timeout_ = watchdog_timeout; }
   uint32_t get_watchdog_timeout() const { return this->watchdog_timeout_; }
   void set_follow_redirects(bool follow_redirects) { this->follow_redirects_ = follow_redirects; }
@@ -242,24 +377,28 @@ template<typename... Ts> class HttpRequestSendAction : public Action<Ts...> {
       return;
     }
 
-    size_t content_length = container->content_length;
-    size_t max_length = std::min(content_length, this->max_response_buffer_size_);
-
+    size_t max_length = this->max_response_buffer_size_;
 #ifdef USE_HTTP_REQUEST_RESPONSE
     if (this->capture_response_.value(x...)) {
       std::string response_body;
       RAMAllocator<uint8_t> allocator;
       uint8_t *buf = allocator.allocate(max_length);
       if (buf != nullptr) {
+        // NOTE: HttpContainer::read() has non-BSD socket semantics - see top of this file
+        // Use http_read_loop_result() helper instead of checking return values directly
         size_t read_index = 0;
+        uint32_t last_data_time = millis();
+        const uint32_t read_timeout = this->parent_->get_timeout();
         while (container->get_bytes_read() < max_length) {
-          int read = container->read(buf + read_index, std::min<size_t>(max_length - read_index, 512));
-          if (read <= 0) {
-            break;
-          }
+          int read_or_error = container->read(buf + read_index, std::min<size_t>(max_length - read_index, 512));
           App.feed_wdt();
           yield();
-          read_index += read;
+          auto result = http_read_loop_result(read_or_error, last_data_time, read_timeout);
+          if (result == HttpReadLoopResult::RETRY)
+            continue;
+          if (result != HttpReadLoopResult::DATA)
+            break;  // ERROR or TIMEOUT
+          read_index += read_or_error;
         }
         response_body.reserve(read_index);
         response_body.assign((char *) buf, read_index);
diff --git a/esphome/components/http_request/http_request_arduino.cpp b/esphome/components/http_request/http_request_arduino.cpp
index a653942b18..8ec4d2bc4b 100644
--- a/esphome/components/http_request/http_request_arduino.cpp
+++ b/esphome/components/http_request/http_request_arduino.cpp
@@ -139,6 +139,23 @@ std::shared_ptr<HttpContainer> HttpRequestArduino::perform(const std::string &ur
   return container;
 }
 
+// Arduino HTTP read implementation
+//
+// WARNING: Return values differ from BSD sockets! See http_request.h for full documentation.
+//
+// Arduino's WiFiClient is inherently non-blocking - available() returns 0 when
+// no data is ready. We use connected() to distinguish "no data yet" from
+// "connection closed".
+//
+// WiFiClient behavior:
+//   available() > 0: data ready to read
+//   available() == 0 && connected(): no data yet, still connected
+//   available() == 0 && !connected(): connection closed
+//
+// We normalize to HttpContainer::read() contract (NOT BSD socket semantics!):
+//   > 0: bytes read
+//   0: no data yet, retry            <-- NOTE: 0 means retry, NOT EOF!
+//   < 0: error/connection closed     <-- connection closed returns -1, not 0
 int HttpContainerArduino::read(uint8_t *buf, size_t max_len) {
   const uint32_t start = millis();
   watchdog::WatchdogManager wdm(this->parent_->get_watchdog_timeout());
@@ -146,7 +163,7 @@ int HttpContainerArduino::read(uint8_t *buf, size_t max_len) {
   WiFiClient *stream_ptr = this->client_.getStreamPtr();
   if (stream_ptr == nullptr) {
     ESP_LOGE(TAG, "Stream pointer vanished!");
-    return -1;
+    return HTTP_ERROR_CONNECTION_CLOSED;
   }
 
   int available_data = stream_ptr->available();
@@ -154,7 +171,15 @@ int HttpContainerArduino::read(uint8_t *buf, size_t max_len) {
 
   if (bufsize == 0) {
     this->duration_ms += (millis() - start);
-    return 0;
+    // Check if we've read all expected content
+    if (this->bytes_read_ >= this->content_length) {
+      return 0;  // All content read successfully
+    }
+    // No data available - check if connection is still open
+    if (!stream_ptr->connected()) {
+      return HTTP_ERROR_CONNECTION_CLOSED;  // Connection closed prematurely
+    }
+    return 0;  // No data yet, caller should retry
   }
 
   App.feed_wdt();
diff --git a/esphome/components/http_request/http_request_idf.cpp b/esphome/components/http_request/http_request_idf.cpp
index 725a9c1c1e..b6fb7f7ea9 100644
--- a/esphome/components/http_request/http_request_idf.cpp
+++ b/esphome/components/http_request/http_request_idf.cpp
@@ -89,7 +89,7 @@ std::shared_ptr<HttpContainer> HttpRequestIDF::perform(const std::string &url, c
   config.max_redirection_count = this->redirect_limit_;
   config.auth_type = HTTP_AUTH_TYPE_BASIC;
 #if CONFIG_MBEDTLS_CERTIFICATE_BUNDLE
-  if (secure) {
+  if (secure && this->verify_ssl_) {
     config.crt_bundle_attach = esp_crt_bundle_attach;
   }
 #endif
@@ -209,32 +209,57 @@ std::shared_ptr<HttpContainer> HttpRequestIDF::perform(const std::string &url, c
   return container;
 }
 
+// ESP-IDF HTTP read implementation (blocking mode)
+//
+// WARNING: Return values differ from BSD sockets! See http_request.h for full documentation.
+//
+// esp_http_client_read() in blocking mode returns:
+//   > 0: bytes read
+//   0: connection closed (end of stream)
+//   < 0: error
+//
+// We normalize to HttpContainer::read() contract:
+//   > 0: bytes read
+//   0: no data yet / all content read (caller should check bytes_read vs content_length)
+//   < 0: error/connection closed
 int HttpContainerIDF::read(uint8_t *buf, size_t max_len) {
   const uint32_t start = millis();
   watchdog::WatchdogManager wdm(this->parent_->get_watchdog_timeout());
 
-  int bufsize = std::min(max_len, this->content_length - this->bytes_read_);
-
-  if (bufsize == 0) {
-    this->duration_ms += (millis() - start);
-    return 0;
+  // Check if we've already read all expected content
+  if (this->bytes_read_ >= this->content_length) {
+    return 0;  // All content read successfully
   }
 
   this->feed_wdt();
-  int read_len = esp_http_client_read(this->client_, (char *) buf, bufsize);
+  int read_len_or_error = esp_http_client_read(this->client_, (char *) buf, max_len);
   this->feed_wdt();
-  this->bytes_read_ += read_len;
 
   this->duration_ms += (millis() - start);
 
-  return read_len;
+  if (read_len_or_error > 0) {
+    this->bytes_read_ += read_len_or_error;
+    return read_len_or_error;
+  }
+
+  // Connection closed by server before all content received
+  if (read_len_or_error == 0) {
+    return HTTP_ERROR_CONNECTION_CLOSED;
+  }
+
+  // Negative value - error, return the actual error code for debugging
+  return read_len_or_error;
 }
 
 void HttpContainerIDF::end() {
+  if (this->client_ == nullptr) {
+    return;  // Already cleaned up
+  }
   watchdog::WatchdogManager wdm(this->parent_->get_watchdog_timeout());
 
   esp_http_client_close(this->client_);
   esp_http_client_cleanup(this->client_);
+  this->client_ = nullptr;
 }
 
 void HttpContainerIDF::feed_wdt() {
diff --git a/esphome/components/http_request/http_request_idf.h b/esphome/components/http_request/http_request_idf.h
index 4dc4736423..0fae67f5bc 100644
--- a/esphome/components/http_request/http_request_idf.h
+++ b/esphome/components/http_request/http_request_idf.h
@@ -34,6 +34,7 @@ class HttpRequestIDF : public HttpRequestComponent {
 
   void set_buffer_size_rx(uint16_t buffer_size_rx) { this->buffer_size_rx_ = buffer_size_rx; }
   void set_buffer_size_tx(uint16_t buffer_size_tx) { this->buffer_size_tx_ = buffer_size_tx; }
+  void set_verify_ssl(bool verify_ssl) { this->verify_ssl_ = verify_ssl; }
 
  protected:
   std::shared_ptr<HttpContainer> perform(const std::string &url, const std::string &method, const std::string &body,
@@ -42,6 +43,7 @@ class HttpRequestIDF : public HttpRequestComponent {
   // if zero ESP-IDF will use DEFAULT_HTTP_BUF_SIZE
   uint16_t buffer_size_rx_{};
   uint16_t buffer_size_tx_{};
+  bool verify_ssl_{true};
 
   /// @brief Monitors the http client events to gather response headers
   static esp_err_t http_event_handler(esp_http_client_event_t *evt);
diff --git a/esphome/components/http_request/ota/ota_http_request.cpp b/esphome/components/http_request/ota/ota_http_request.cpp
index 2a7db9137f..6c77e75d8c 100644
--- a/esphome/components/http_request/ota/ota_http_request.cpp
+++ b/esphome/components/http_request/ota/ota_http_request.cpp
@@ -115,39 +115,47 @@ uint8_t OtaHttpRequestComponent::do_ota_() {
     return error_code;
   }
 
+  // NOTE: HttpContainer::read() has non-BSD socket semantics - see http_request.h
+  // Use http_read_loop_result() helper instead of checking return values directly
+  uint32_t last_data_time = millis();
+  const uint32_t read_timeout = this->parent_->get_timeout();
+
   while (container->get_bytes_read() < container->content_length) {
-    // read a maximum of chunk_size bytes into buf. (real read size returned)
-    int bufsize = container->read(buf, OtaHttpRequestComponent::HTTP_RECV_BUFFER);
-    ESP_LOGVV(TAG, "bytes_read_ = %u, body_length_ = %u, bufsize = %i", container->get_bytes_read(),
-              container->content_length, bufsize);
+    // read a maximum of chunk_size bytes into buf. (real read size returned, or negative error code)
+    int bufsize_or_error = container->read(buf, OtaHttpRequestComponent::HTTP_RECV_BUFFER);
+    ESP_LOGVV(TAG, "bytes_read_ = %u, body_length_ = %u, bufsize_or_error = %i", container->get_bytes_read(),
+              container->content_length, bufsize_or_error);
 
     // feed watchdog and give other tasks a chance to run
     App.feed_wdt();
     yield();
 
-    // Exit loop if no data available (stream closed or end of data)
-    if (bufsize <= 0) {
-      if (bufsize < 0) {
-        ESP_LOGE(TAG, "Stream closed with error");
-        this->cleanup_(std::move(backend), container);
-        return OTA_CONNECTION_ERROR;
+    auto result = http_read_loop_result(bufsize_or_error, last_data_time, read_timeout);
+    if (result == HttpReadLoopResult::RETRY)
+      continue;
+    if (result != HttpReadLoopResult::DATA) {
+      if (result == HttpReadLoopResult::TIMEOUT) {
+        ESP_LOGE(TAG, "Timeout reading data");
+      } else {
+        ESP_LOGE(TAG, "Error reading data: %d", bufsize_or_error);
       }
-      // bufsize == 0: no more data available, exit loop
-      break;
+      this->cleanup_(std::move(backend), container);
+      return OTA_CONNECTION_ERROR;
     }
 
-    if (bufsize <= OtaHttpRequestComponent::HTTP_RECV_BUFFER) {
+    // At this point bufsize_or_error > 0, so it's a valid size
+    if (bufsize_or_error <= OtaHttpRequestComponent::HTTP_RECV_BUFFER) {
       // add read bytes to MD5
-      md5_receive.add(buf, bufsize);
+      md5_receive.add(buf, bufsize_or_error);
 
       // write bytes to OTA backend
       this->update_started_ = true;
-      error_code = backend->write(buf, bufsize);
+      error_code = backend->write(buf, bufsize_or_error);
       if (error_code != ota::OTA_RESPONSE_OK) {
         // error code explanation available at
         // https://github.com/esphome/esphome/blob/dev/esphome/components/ota/ota_backend.h
         ESP_LOGE(TAG, "Error code (%02X) writing binary data to flash at offset %d and size %d", error_code,
-                 container->get_bytes_read() - bufsize, container->content_length);
+                 container->get_bytes_read() - bufsize_or_error, container->content_length);
         this->cleanup_(std::move(backend), container);
         return error_code;
       }
@@ -244,19 +252,19 @@ bool OtaHttpRequestComponent::http_get_md5_() {
   }
 
   this->md5_expected_.resize(MD5_SIZE);
-  int read_len = 0;
-  while (container->get_bytes_read() < MD5_SIZE) {
-    read_len = container->read((uint8_t *) this->md5_expected_.data(), MD5_SIZE);
-    if (read_len <= 0) {
-      break;
-    }
-    App.feed_wdt();
-    yield();
-  }
+  auto result = http_read_fully(container.get(), (uint8_t *) this->md5_expected_.data(), MD5_SIZE, MD5_SIZE,
+                                this->parent_->get_timeout());
   container->end();
 
-  ESP_LOGV(TAG, "Read len: %u, MD5 expected: %u", read_len, MD5_SIZE);
-  return read_len == MD5_SIZE;
+  if (result.status != HttpReadStatus::OK) {
+    if (result.status == HttpReadStatus::TIMEOUT) {
+      ESP_LOGE(TAG, "Timeout reading MD5");
+    } else {
+      ESP_LOGE(TAG, "Error reading MD5: %d", result.error_code);
+    }
+    return false;
+  }
+  return true;
 }
 
 bool OtaHttpRequestComponent::validate_url_(const std::string &url) {
diff --git a/esphome/components/http_request/update/http_request_update.cpp b/esphome/components/http_request/update/http_request_update.cpp
index 82b391e01f..c63e55d159 100644
--- a/esphome/components/http_request/update/http_request_update.cpp
+++ b/esphome/components/http_request/update/http_request_update.cpp
@@ -11,7 +11,12 @@ namespace http_request {
 
 // The update function runs in a task only on ESP32s.
 #ifdef USE_ESP32
-#define UPDATE_RETURN vTaskDelete(nullptr)  // Delete the current update task
+// vTaskDelete doesn't return, but clang-tidy doesn't know that
+#define UPDATE_RETURN \
+  do { \
+    vTaskDelete(nullptr); \
+    __builtin_unreachable(); \
+  } while (0)
 #else
 #define UPDATE_RETURN return
 #endif
@@ -70,19 +75,21 @@ void HttpRequestUpdate::update_task(void *params) {
     UPDATE_RETURN;
   }
 
-  size_t read_index = 0;
-  while (container->get_bytes_read() < container->content_length) {
-    int read_bytes = container->read(data + read_index, MAX_READ_SIZE);
-
-    yield();
-
-    if (read_bytes <= 0) {
-      // Network error or connection closed - break to avoid infinite loop
-      break;
+  auto read_result = http_read_fully(container.get(), data, container->content_length, MAX_READ_SIZE,
+                                     this_update->request_parent_->get_timeout());
+  if (read_result.status != HttpReadStatus::OK) {
+    if (read_result.status == HttpReadStatus::TIMEOUT) {
+      ESP_LOGE(TAG, "Timeout reading manifest");
+    } else {
+      ESP_LOGE(TAG, "Error reading manifest: %d", read_result.error_code);
     }
-
-    read_index += read_bytes;
+    // Defer to main loop to avoid race condition on component_state_ read-modify-write
+    this_update->defer([this_update]() { this_update->status_set_error(LOG_STR("Failed to read manifest")); });
+    allocator.deallocate(data, container->content_length);
+    container->end();
+    UPDATE_RETURN;
   }
+  size_t read_index = container->get_bytes_read();
 
   bool valid = false;
   {  // Ensures the response string falls out of scope and deallocates before the task ends
diff --git a/esphome/components/hub75/display.py b/esphome/components/hub75/display.py
index 20c731e730..0eeb4bba33 100644
--- a/esphome/components/hub75/display.py
+++ b/esphome/components/hub75/display.py
@@ -1,3 +1,4 @@
+import logging
 from typing import Any
 
 from esphome import automation, pins
@@ -18,13 +19,16 @@ from esphome.const import (
     CONF_ROTATION,
     CONF_UPDATE_INTERVAL,
 )
-from esphome.core import ID
+from esphome.core import ID, EnumValue
 from esphome.cpp_generator import MockObj, TemplateArgsType
 import esphome.final_validate as fv
+from esphome.helpers import add_class_to_obj
 from esphome.types import ConfigType
 
 from . import boards, hub75_ns
 
+_LOGGER = logging.getLogger(__name__)
+
 DEPENDENCIES = ["esp32"]
 CODEOWNERS = ["@stuartparmenter"]
 
@@ -120,13 +124,51 @@ PANEL_LAYOUTS = {
 }
 
 Hub75ScanWiring = cg.global_ns.enum("Hub75ScanWiring", is_class=True)
-SCAN_PATTERNS = {
+SCAN_WIRINGS = {
     "STANDARD_TWO_SCAN": Hub75ScanWiring.STANDARD_TWO_SCAN,
-    "FOUR_SCAN_16PX_HIGH": Hub75ScanWiring.FOUR_SCAN_16PX_HIGH,
-    "FOUR_SCAN_32PX_HIGH": Hub75ScanWiring.FOUR_SCAN_32PX_HIGH,
-    "FOUR_SCAN_64PX_HIGH": Hub75ScanWiring.FOUR_SCAN_64PX_HIGH,
+    "SCAN_1_4_16PX_HIGH": Hub75ScanWiring.SCAN_1_4_16PX_HIGH,
+    "SCAN_1_8_32PX_HIGH": Hub75ScanWiring.SCAN_1_8_32PX_HIGH,
+    "SCAN_1_8_40PX_HIGH": Hub75ScanWiring.SCAN_1_8_40PX_HIGH,
+    "SCAN_1_8_64PX_HIGH": Hub75ScanWiring.SCAN_1_8_64PX_HIGH,
 }
 
+# Deprecated scan wiring names - mapped to new names
+DEPRECATED_SCAN_WIRINGS = {
+    "FOUR_SCAN_16PX_HIGH": "SCAN_1_4_16PX_HIGH",
+    "FOUR_SCAN_32PX_HIGH": "SCAN_1_8_32PX_HIGH",
+    "FOUR_SCAN_64PX_HIGH": "SCAN_1_8_64PX_HIGH",
+}
+
+
+def _validate_scan_wiring(value):
+    """Validate scan_wiring with deprecation warnings for old names."""
+    value = cv.string(value).upper().replace(" ", "_")
+
+    # Check if using deprecated name
+    # Remove deprecated names in 2026.7.0
+    if value in DEPRECATED_SCAN_WIRINGS:
+        new_name = DEPRECATED_SCAN_WIRINGS[value]
+        _LOGGER.warning(
+            "Scan wiring '%s' is deprecated and will be removed in ESPHome 2026.7.0. "
+            "Please use '%s' instead.",
+            value,
+            new_name,
+        )
+        value = new_name
+
+    # Validate against allowed values
+    if value not in SCAN_WIRINGS:
+        raise cv.Invalid(
+            f"Unknown scan wiring '{value}'. "
+            f"Valid options are: {', '.join(sorted(SCAN_WIRINGS.keys()))}"
+        )
+
+    # Return as EnumValue like cv.enum does
+    result = add_class_to_obj(value, EnumValue)
+    result.enum_value = SCAN_WIRINGS[value]
+    return result
+
+
 Hub75ClockSpeed = cg.global_ns.enum("Hub75ClockSpeed", is_class=True)
 CLOCK_SPEEDS = {
     "8MHZ": Hub75ClockSpeed.HZ_8M,
@@ -382,9 +424,7 @@ CONFIG_SCHEMA = cv.All(
             cv.Optional(CONF_LAYOUT_COLS): cv.positive_int,
             cv.Optional(CONF_LAYOUT): cv.enum(PANEL_LAYOUTS, upper=True, space="_"),
             # Panel hardware configuration
-            cv.Optional(CONF_SCAN_WIRING): cv.enum(
-                SCAN_PATTERNS, upper=True, space="_"
-            ),
+            cv.Optional(CONF_SCAN_WIRING): _validate_scan_wiring,
             cv.Optional(CONF_SHIFT_DRIVER): cv.enum(SHIFT_DRIVERS, upper=True),
             # Display configuration
             cv.Optional(CONF_DOUBLE_BUFFER): cv.boolean,
@@ -547,7 +587,7 @@ def _build_config_struct(
 async def to_code(config: ConfigType) -> None:
     add_idf_component(
         name="esphome/esp-hub75",
-        ref="0.2.2",
+        ref="0.3.0",
     )
 
     # Set compile-time configuration via build flags (so external library sees them)
diff --git a/esphome/components/i2c/i2c.cpp b/esphome/components/i2c/i2c.cpp
index f8c7a1b40b..c1e7336ce4 100644
--- a/esphome/components/i2c/i2c.cpp
+++ b/esphome/components/i2c/i2c.cpp
@@ -42,8 +42,8 @@ ErrorCode I2CDevice::read_register16(uint16_t a_register, uint8_t *data, size_t
 }
 
 ErrorCode I2CDevice::write_register(uint8_t a_register, const uint8_t *data, size_t len) const {
-  SmallBufferWithHeapFallback<17> buffer_alloc;  // Most I2C writes are <= 16 bytes
-  uint8_t *buffer = buffer_alloc.get(len + 1);
+  SmallBufferWithHeapFallback<17> buffer_alloc(len + 1);  // Most I2C writes are <= 16 bytes
+  uint8_t *buffer = buffer_alloc.get();
 
   buffer[0] = a_register;
   std::copy(data, data + len, buffer + 1);
@@ -51,8 +51,8 @@ ErrorCode I2CDevice::write_register(uint8_t a_register, const uint8_t *data, siz
 }
 
 ErrorCode I2CDevice::write_register16(uint16_t a_register, const uint8_t *data, size_t len) const {
-  SmallBufferWithHeapFallback<18> buffer_alloc;  // Most I2C writes are <= 16 bytes + 2 for register
-  uint8_t *buffer = buffer_alloc.get(len + 2);
+  SmallBufferWithHeapFallback<18> buffer_alloc(len + 2);  // Most I2C writes are <= 16 bytes + 2 for register
+  uint8_t *buffer = buffer_alloc.get();
 
   buffer[0] = a_register >> 8;
   buffer[1] = a_register;
diff --git a/esphome/components/i2c/i2c_bus.h b/esphome/components/i2c/i2c_bus.h
index 1acbe506a3..3de5d5ca7b 100644
--- a/esphome/components/i2c/i2c_bus.h
+++ b/esphome/components/i2c/i2c_bus.h
@@ -11,22 +11,6 @@
 namespace esphome {
 namespace i2c {
 
-/// @brief Helper class for efficient buffer allocation - uses stack for small sizes, heap for large
-template<size_t STACK_SIZE> class SmallBufferWithHeapFallback {
- public:
-  uint8_t *get(size_t size) {
-    if (size <= STACK_SIZE) {
-      return this->stack_buffer_;
-    }
-    this->heap_buffer_ = std::unique_ptr<uint8_t[]>(new uint8_t[size]);
-    return this->heap_buffer_.get();
-  }
-
- private:
-  uint8_t stack_buffer_[STACK_SIZE];
-  std::unique_ptr<uint8_t[]> heap_buffer_;
-};
-
 /// @brief Error codes returned by I2CBus and I2CDevice methods
 enum ErrorCode {
   NO_ERROR = 0,                ///< No error found during execution of method
@@ -92,8 +76,8 @@ class I2CBus {
       total_len += read_buffers[i].len;
     }
 
-    SmallBufferWithHeapFallback<128> buffer_alloc;  // Most I2C reads are small
-    uint8_t *buffer = buffer_alloc.get(total_len);
+    SmallBufferWithHeapFallback<128> buffer_alloc(total_len);  // Most I2C reads are small
+    uint8_t *buffer = buffer_alloc.get();
 
     auto err = this->write_readv(address, nullptr, 0, buffer, total_len);
     if (err != ERROR_OK)
@@ -116,8 +100,8 @@ class I2CBus {
       total_len += write_buffers[i].len;
     }
 
-    SmallBufferWithHeapFallback<128> buffer_alloc;  // Most I2C writes are small
-    uint8_t *buffer = buffer_alloc.get(total_len);
+    SmallBufferWithHeapFallback<128> buffer_alloc(total_len);  // Most I2C writes are small
+    uint8_t *buffer = buffer_alloc.get();
 
     size_t pos = 0;
     for (size_t i = 0; i != count; i++) {
diff --git a/esphome/components/ili9xxx/display.py b/esphome/components/ili9xxx/display.py
index 9588bccd55..bfb2300f4f 100644
--- a/esphome/components/ili9xxx/display.py
+++ b/esphome/components/ili9xxx/display.py
@@ -223,7 +223,7 @@ async def to_code(config):
     var = cg.Pvariable(config[CONF_ID], rhs)
 
     await display.register_display(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
     if init_sequences := config.get(CONF_INIT_SEQUENCE):
diff --git a/esphome/components/infrared/infrared.cpp b/esphome/components/infrared/infrared.cpp
index 294d69e523..4431869951 100644
--- a/esphome/components/infrared/infrared.cpp
+++ b/esphome/components/infrared/infrared.cpp
@@ -19,12 +19,12 @@ InfraredCall &InfraredCall::set_carrier_frequency(uint32_t frequency) {
 InfraredCall &InfraredCall::set_raw_timings(const std::vector<int32_t> &timings) {
   this->raw_timings_ = &timings;
   this->packed_data_ = nullptr;
-  this->base85_ptr_ = nullptr;
+  this->base64url_ptr_ = nullptr;
   return *this;
 }
 
-InfraredCall &InfraredCall::set_raw_timings_base85(const std::string &base85) {
-  this->base85_ptr_ = &base85;
+InfraredCall &InfraredCall::set_raw_timings_base64url(const std::string &base64url) {
+  this->base64url_ptr_ = &base64url;
   this->raw_timings_ = nullptr;
   this->packed_data_ = nullptr;
   return *this;
@@ -35,7 +35,7 @@ InfraredCall &InfraredCall::set_raw_timings_packed(const uint8_t *data, uint16_t
   this->packed_length_ = length;
   this->packed_count_ = count;
   this->raw_timings_ = nullptr;
-  this->base85_ptr_ = nullptr;
+  this->base64url_ptr_ = nullptr;
   return *this;
 }
 
@@ -101,13 +101,22 @@ void Infrared::control(const InfraredCall &call) {
                                                call.get_packed_count());
     ESP_LOGD(TAG, "Transmitting packed raw timings: count=%u, repeat=%u", call.get_packed_count(),
              call.get_repeat_count());
-  } else if (call.is_base85()) {
-    // Decode base85 directly into transmit buffer (zero heap allocations)
-    if (!transmit_data->set_data_from_base85(call.get_base85_data())) {
-      ESP_LOGE(TAG, "Invalid base85 data");
+  } else if (call.is_base64url()) {
+    // Decode base64url (URL-safe) into transmit buffer
+    if (!transmit_data->set_data_from_base64url(call.get_base64url_data())) {
+      ESP_LOGE(TAG, "Invalid base64url data");
       return;
     }
-    ESP_LOGD(TAG, "Transmitting base85 raw timings: count=%zu, repeat=%u", transmit_data->get_data().size(),
+    // Sanity check: validate timing values are within reasonable bounds
+    constexpr int32_t max_timing_us = 500000;  // 500ms absolute max
+    for (int32_t timing : transmit_data->get_data()) {
+      int32_t abs_timing = timing < 0 ? -timing : timing;
+      if (abs_timing > max_timing_us) {
+        ESP_LOGE(TAG, "Invalid timing value: %d µs (max %d)", timing, max_timing_us);
+        return;
+      }
+    }
+    ESP_LOGD(TAG, "Transmitting base64url raw timings: count=%zu, repeat=%u", transmit_data->get_data().size(),
              call.get_repeat_count());
   } else {
     // From vector (lambdas/automations)
diff --git a/esphome/components/infrared/infrared.h b/esphome/components/infrared/infrared.h
index ba426c9daa..59535f499a 100644
--- a/esphome/components/infrared/infrared.h
+++ b/esphome/components/infrared/infrared.h
@@ -40,11 +40,11 @@ class InfraredCall {
   /// @note Usage: Primarily for lambdas/automations where the vector is in scope.
   InfraredCall &set_raw_timings(const std::vector<int32_t> &timings);
 
-  /// Set the raw timings from base85-encoded int32 data
+  /// Set the raw timings from base64url-encoded little-endian int32 data
   /// @note Lifetime: Stores a pointer to the string. The string must outlive perform().
-  /// @note Usage: For web_server where the encoded string is on the stack.
+  /// @note Usage: For web_server - base64url is fully URL-safe (uses '-' and '_').
   /// @note Decoding happens at perform() time, directly into the transmit buffer.
-  InfraredCall &set_raw_timings_base85(const std::string &base85);
+  InfraredCall &set_raw_timings_base64url(const std::string &base64url);
 
   /// Set the raw timings from packed protobuf sint32 data (zigzag + varint encoded)
   /// @note Lifetime: Stores a pointer to the buffer. The buffer must outlive perform().
@@ -59,18 +59,18 @@ class InfraredCall {
 
   /// Get the carrier frequency
   const optional<uint32_t> &get_carrier_frequency() const { return this->carrier_frequency_; }
-  /// Get the raw timings (only valid if set via set_raw_timings, not packed or base85)
+  /// Get the raw timings (only valid if set via set_raw_timings)
   const std::vector<int32_t> &get_raw_timings() const { return *this->raw_timings_; }
-  /// Check if raw timings have been set (vector, packed, or base85)
+  /// Check if raw timings have been set (any format)
   bool has_raw_timings() const {
-    return this->raw_timings_ != nullptr || this->packed_data_ != nullptr || this->base85_ptr_ != nullptr;
+    return this->raw_timings_ != nullptr || this->packed_data_ != nullptr || this->base64url_ptr_ != nullptr;
   }
   /// Check if using packed data format
   bool is_packed() const { return this->packed_data_ != nullptr; }
-  /// Check if using base85 data format
-  bool is_base85() const { return this->base85_ptr_ != nullptr; }
-  /// Get the base85 data string
-  const std::string &get_base85_data() const { return *this->base85_ptr_; }
+  /// Check if using base64url data format
+  bool is_base64url() const { return this->base64url_ptr_ != nullptr; }
+  /// Get the base64url data string
+  const std::string &get_base64url_data() const { return *this->base64url_ptr_; }
   /// Get packed data (only valid if set via set_raw_timings_packed)
   const uint8_t *get_packed_data() const { return this->packed_data_; }
   uint16_t get_packed_length() const { return this->packed_length_; }
@@ -84,8 +84,8 @@ class InfraredCall {
   optional<uint32_t> carrier_frequency_;
   // Pointer to vector-based timings (caller-owned, must outlive perform())
   const std::vector<int32_t> *raw_timings_{nullptr};
-  // Pointer to base85-encoded string (caller-owned, must outlive perform())
-  const std::string *base85_ptr_{nullptr};
+  // Pointer to base64url-encoded string (caller-owned, must outlive perform())
+  const std::string *base64url_ptr_{nullptr};
   // Pointer to packed protobuf buffer (caller-owned, must outlive perform())
   const uint8_t *packed_data_{nullptr};
   uint16_t packed_length_{0};
diff --git a/esphome/components/json/__init__.py b/esphome/components/json/__init__.py
index 4cd737c60d..28fdcd41ef 100644
--- a/esphome/components/json/__init__.py
+++ b/esphome/components/json/__init__.py
@@ -1,6 +1,6 @@
 import esphome.codegen as cg
 import esphome.config_validation as cv
-from esphome.core import CoroPriority, coroutine_with_priority
+from esphome.core import CORE, CoroPriority, coroutine_with_priority
 
 CODEOWNERS = ["@esphome/core"]
 json_ns = cg.esphome_ns.namespace("json")
@@ -12,6 +12,11 @@ CONFIG_SCHEMA = cv.All(
 
 @coroutine_with_priority(CoroPriority.BUS)
 async def to_code(config):
-    cg.add_library("bblanchon/ArduinoJson", "7.4.2")
+    if CORE.is_esp32:
+        from esphome.components.esp32 import add_idf_component
+
+        add_idf_component(name="bblanchon/arduinojson", ref="7.4.2")
+    else:
+        cg.add_library("bblanchon/ArduinoJson", "7.4.2")
     cg.add_define("USE_JSON")
     cg.add_global(json_ns.using)
diff --git a/esphome/components/libretiny/__init__.py b/esphome/components/libretiny/__init__.py
index 8318722b80..503ec7e167 100644
--- a/esphome/components/libretiny/__init__.py
+++ b/esphome/components/libretiny/__init__.py
@@ -382,4 +382,11 @@ async def component_to_code(config):
             "custom_options.sys_config#h", _BK7231N_SYS_CONFIG_OPTIONS
         )
 
+    # Disable LWIP statistics to save RAM - not needed in production
+    # Must explicitly disable all sub-stats to avoid redefinition warnings
+    cg.add_platformio_option(
+        "custom_options.lwip",
+        ["LWIP_STATS=0", "MEM_STATS=0", "MEMP_STATS=0"],
+    )
+
     await cg.register_component(var, config)
diff --git a/esphome/components/libretiny/preferences.cpp b/esphome/components/libretiny/preferences.cpp
index 68bc279767..978dcce3fa 100644
--- a/esphome/components/libretiny/preferences.cpp
+++ b/esphome/components/libretiny/preferences.cpp
@@ -166,8 +166,8 @@ class LibreTinyPreferences : public ESPPreferences {
       return true;
     }
 
-    // Allocate buffer on heap to avoid stack allocation for large data
-    auto stored_data = std::make_unique<uint8_t[]>(kv.value_len);
+    // Most preferences are small, use stack buffer with heap fallback for large ones
+    SmallBufferWithHeapFallback<256> stored_data(kv.value_len);
     fdb_blob_make(&this->blob, stored_data.get(), kv.value_len);
     size_t actual_len = fdb_kv_get_blob(db, key_str, &this->blob);
     if (actual_len != kv.value_len) {
diff --git a/esphome/components/light/light_json_schema.cpp b/esphome/components/light/light_json_schema.cpp
index f370980737..631f59221f 100644
--- a/esphome/components/light/light_json_schema.cpp
+++ b/esphome/components/light/light_json_schema.cpp
@@ -1,4 +1,5 @@
 #include "light_json_schema.h"
+#include "color_mode.h"
 #include "light_output.h"
 #include "esphome/core/progmem.h"
 
@@ -8,29 +9,32 @@ namespace esphome::light {
 
 // See https://www.home-assistant.io/integrations/light.mqtt/#json-schema for documentation on the schema
 
-// Get JSON string for color mode using linear search (avoids large switch jump table)
-static const char *get_color_mode_json_str(ColorMode mode) {
-  // Parallel arrays: mode values and their corresponding strings
-  // Uses less RAM than a switch jump table on sparse enum values
-  static constexpr ColorMode MODES[] = {
-      ColorMode::ON_OFF,
-      ColorMode::BRIGHTNESS,
-      ColorMode::WHITE,
-      ColorMode::COLOR_TEMPERATURE,
-      ColorMode::COLD_WARM_WHITE,
-      ColorMode::RGB,
-      ColorMode::RGB_WHITE,
-      ColorMode::RGB_COLOR_TEMPERATURE,
-      ColorMode::RGB_COLD_WARM_WHITE,
-  };
-  static constexpr const char *STRINGS[] = {
-      "onoff", "brightness", "white", "color_temp", "cwww", "rgb", "rgbw", "rgbct", "rgbww",
-  };
-  for (size_t i = 0; i < sizeof(MODES) / sizeof(MODES[0]); i++) {
-    if (MODES[i] == mode)
-      return STRINGS[i];
+// Get JSON string for color mode.
+// ColorMode enum values are sparse bitmasks (0, 1, 3, 7, 11, 19, 35, 39, 47, 51) which would
+// generate a large jump table. Converting to bit index (0-9) allows a compact switch.
+static ProgmemStr get_color_mode_json_str(ColorMode mode) {
+  switch (ColorModeBitPolicy::to_bit(mode)) {
+    case 1:
+      return ESPHOME_F("onoff");
+    case 2:
+      return ESPHOME_F("brightness");
+    case 3:
+      return ESPHOME_F("white");
+    case 4:
+      return ESPHOME_F("color_temp");
+    case 5:
+      return ESPHOME_F("cwww");
+    case 6:
+      return ESPHOME_F("rgb");
+    case 7:
+      return ESPHOME_F("rgbw");
+    case 8:
+      return ESPHOME_F("rgbct");
+    case 9:
+      return ESPHOME_F("rgbww");
+    default:
+      return nullptr;
   }
-  return nullptr;
 }
 
 void LightJSONSchema::dump_json(LightState &state, JsonObject root) {
@@ -44,7 +48,7 @@ void LightJSONSchema::dump_json(LightState &state, JsonObject root) {
   auto values = state.remote_values;
 
   const auto color_mode = values.get_color_mode();
-  const char *mode_str = get_color_mode_json_str(color_mode);
+  const auto *mode_str = get_color_mode_json_str(color_mode);
   if (mode_str != nullptr) {
     root[ESPHOME_F("color_mode")] = mode_str;
   }
diff --git a/esphome/components/lightwaverf/lightwaverf.cpp b/esphome/components/lightwaverf/lightwaverf.cpp
index 31ac1fc576..2b44195c97 100644
--- a/esphome/components/lightwaverf/lightwaverf.cpp
+++ b/esphome/components/lightwaverf/lightwaverf.cpp
@@ -1,3 +1,4 @@
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
 #ifdef USE_ESP8266
@@ -44,13 +45,16 @@ void LightWaveRF::send_rx(const std::vector<uint8_t> &msg, uint8_t repeats, bool
 }
 
 void LightWaveRF::print_msg_(uint8_t *msg, uint8_t len) {
-  char buffer[65];
+#if ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_DEBUG
+  char buffer[65];  // max 10 entries * 6 chars + null
   ESP_LOGD(TAG, " Received code (len:%i): ", len);
 
+  size_t pos = 0;
   for (int i = 0; i < len; i++) {
-    sprintf(&buffer[i * 6], "0x%02x, ", msg[i]);
+    pos = buf_append_printf(buffer, sizeof(buffer), pos, "0x%02x, ", msg[i]);
   }
   ESP_LOGD(TAG, "[%s]", buffer);
+#endif
 }
 
 void LightWaveRF::dump_config() {
diff --git a/esphome/components/lock/lock.cpp b/esphome/components/lock/lock.cpp
index aca6ec10f3..9fa1ba3600 100644
--- a/esphome/components/lock/lock.cpp
+++ b/esphome/components/lock/lock.cpp
@@ -28,16 +28,14 @@ const LogString *lock_state_to_string(LockState state) {
 Lock::Lock() : state(LOCK_STATE_NONE) {}
 LockCall Lock::make_call() { return LockCall(this); }
 
-void Lock::lock() {
+void Lock::set_state_(LockState state) {
   auto call = this->make_call();
-  call.set_state(LOCK_STATE_LOCKED);
-  this->control(call);
-}
-void Lock::unlock() {
-  auto call = this->make_call();
-  call.set_state(LOCK_STATE_UNLOCKED);
+  call.set_state(state);
   this->control(call);
 }
+
+void Lock::lock() { this->set_state_(LOCK_STATE_LOCKED); }
+void Lock::unlock() { this->set_state_(LOCK_STATE_UNLOCKED); }
 void Lock::open() {
   if (traits.get_supports_open()) {
     ESP_LOGD(TAG, "'%s' Opening.", this->get_name().c_str());
diff --git a/esphome/components/lock/lock.h b/esphome/components/lock/lock.h
index f77b11b145..b518c8b846 100644
--- a/esphome/components/lock/lock.h
+++ b/esphome/components/lock/lock.h
@@ -156,6 +156,9 @@ class Lock : public EntityBase {
  protected:
   friend LockCall;
 
+  /// Helper for lock/unlock convenience methods
+  void set_state_(LockState state);
+
   /** Perform the open latch action with hardware. This method is optional to implement
    * when creating a new lock.
    *
diff --git a/esphome/components/logger/logger.cpp b/esphome/components/logger/logger.cpp
index 34430dbafa..3a726d4046 100644
--- a/esphome/components/logger/logger.cpp
+++ b/esphome/components/logger/logger.cpp
@@ -1,8 +1,5 @@
 #include "logger.h"
 #include <cinttypes>
-#ifdef USE_ESPHOME_TASK_LOG_BUFFER
-#include <memory>  // For unique_ptr
-#endif
 
 #include "esphome/core/application.h"
 #include "esphome/core/hal.h"
@@ -199,7 +196,8 @@ inline uint8_t Logger::level_for(const char *tag) {
 
 Logger::Logger(uint32_t baud_rate, size_t tx_buffer_size) : baud_rate_(baud_rate), tx_buffer_size_(tx_buffer_size) {
   // add 1 to buffer size for null terminator
-  this->tx_buffer_ = new char[this->tx_buffer_size_ + 1];  // NOLINT
+  // NOLINTNEXTLINE(cppcoreguidelines-owning-memory) - allocated once, never freed
+  this->tx_buffer_ = new char[this->tx_buffer_size_ + 1];
 #if defined(USE_ESP32) || defined(USE_LIBRETINY)
   this->main_task_ = xTaskGetCurrentTaskHandle();
 #elif defined(USE_ZEPHYR)
@@ -212,11 +210,14 @@ Logger::Logger(uint32_t baud_rate, size_t tx_buffer_size) : baud_rate_(baud_rate
 void Logger::init_log_buffer(size_t total_buffer_size) {
 #ifdef USE_HOST
   // Host uses slot count instead of byte size
-  this->log_buffer_ = esphome::make_unique<logger::TaskLogBufferHost>(total_buffer_size);
+  // NOLINTNEXTLINE(cppcoreguidelines-owning-memory) - allocated once, never freed
+  this->log_buffer_ = new logger::TaskLogBufferHost(total_buffer_size);
 #elif defined(USE_ESP32)
-  this->log_buffer_ = esphome::make_unique<logger::TaskLogBuffer>(total_buffer_size);
+  // NOLINTNEXTLINE(cppcoreguidelines-owning-memory) - allocated once, never freed
+  this->log_buffer_ = new logger::TaskLogBuffer(total_buffer_size);
 #elif defined(USE_LIBRETINY)
-  this->log_buffer_ = esphome::make_unique<logger::TaskLogBufferLibreTiny>(total_buffer_size);
+  // NOLINTNEXTLINE(cppcoreguidelines-owning-memory) - allocated once, never freed
+  this->log_buffer_ = new logger::TaskLogBufferLibreTiny(total_buffer_size);
 #endif
 
 #if defined(USE_ESP32) || defined(USE_LIBRETINY)
diff --git a/esphome/components/logger/logger.h b/esphome/components/logger/logger.h
index 3e8538c2ae..fe9cab4993 100644
--- a/esphome/components/logger/logger.h
+++ b/esphome/components/logger/logger.h
@@ -412,11 +412,11 @@ class Logger : public Component {
 #endif
 #ifdef USE_ESPHOME_TASK_LOG_BUFFER
 #ifdef USE_HOST
-  std::unique_ptr<logger::TaskLogBufferHost> log_buffer_;  // Will be initialized with init_log_buffer
+  logger::TaskLogBufferHost *log_buffer_{nullptr};  // Allocated once, never freed
 #elif defined(USE_ESP32)
-  std::unique_ptr<logger::TaskLogBuffer> log_buffer_;  // Will be initialized with init_log_buffer
+  logger::TaskLogBuffer *log_buffer_{nullptr};  // Allocated once, never freed
 #elif defined(USE_LIBRETINY)
-  std::unique_ptr<logger::TaskLogBufferLibreTiny> log_buffer_;  // Will be initialized with init_log_buffer
+  logger::TaskLogBufferLibreTiny *log_buffer_{nullptr};  // Allocated once, never freed
 #endif
 #endif
 
diff --git a/esphome/components/lvgl/widgets/dropdown.py b/esphome/components/lvgl/widgets/dropdown.py
index 9ff183f3dd..ca89bb625b 100644
--- a/esphome/components/lvgl/widgets/dropdown.py
+++ b/esphome/components/lvgl/widgets/dropdown.py
@@ -1,3 +1,4 @@
+from esphome import codegen as cg
 import esphome.config_validation as cv
 from esphome.const import CONF_OPTIONS
 
@@ -24,6 +25,34 @@ from .label import CONF_LABEL
 CONF_DROPDOWN = "dropdown"
 CONF_DROPDOWN_LIST = "dropdown_list"
 
+# Example valid dropdown symbol (left arrow) for error messages
+EXAMPLE_DROPDOWN_SYMBOL = "\U00002190"  # ←
+
+
+def dropdown_symbol_validator(value):
+    """
+    Validate that the dropdown symbol is a single Unicode character
+    with a codepoint of 0x100 (256) or greater.
+    This is required because LVGL uses codepoints below 0x100 for internal symbols.
+    """
+    value = cv.string(value)
+    # len(value) counts Unicode code points, not grapheme clusters or bytes
+    if len(value) != 1:
+        raise cv.Invalid(
+            f"Dropdown symbol must be a single character, got '{value}' with length {len(value)}"
+        )
+    codepoint = ord(value)
+    if codepoint < 0x100:
+        # Format the example symbol as a Unicode escape for the error message
+        example_escape = f"\\U{ord(EXAMPLE_DROPDOWN_SYMBOL):08X}"
+        raise cv.Invalid(
+            f"Dropdown symbol must have a Unicode codepoint of 0x100 (256) or greater. "
+            f"'{value}' has codepoint {codepoint} (0x{codepoint:X}). "
+            f"Use a character like '{example_escape}' ({EXAMPLE_DROPDOWN_SYMBOL}) or other Unicode symbols with codepoint >= 0x100."
+        )
+    return value
+
+
 lv_dropdown_t = LvSelect("LvDropdownType", parents=(LvCompound,))
 
 lv_dropdown_list_t = LvType("lv_dropdown_list_t")
@@ -33,7 +62,7 @@ dropdown_list_spec = WidgetType(
 
 DROPDOWN_BASE_SCHEMA = cv.Schema(
     {
-        cv.Optional(CONF_SYMBOL): lv_text,
+        cv.Optional(CONF_SYMBOL): dropdown_symbol_validator,
         cv.Exclusive(CONF_SELECTED_INDEX, CONF_SELECTED_TEXT): lv_int,
         cv.Exclusive(CONF_SELECTED_TEXT, CONF_SELECTED_TEXT): lv_text,
         cv.Optional(CONF_DROPDOWN_LIST): part_schema(dropdown_list_spec.parts),
@@ -70,7 +99,7 @@ class DropdownType(WidgetType):
         if options := config.get(CONF_OPTIONS):
             lv_add(w.var.set_options(options))
         if symbol := config.get(CONF_SYMBOL):
-            lv.dropdown_set_symbol(w.var.obj, await lv_text.process(symbol))
+            lv.dropdown_set_symbol(w.var.obj, cg.safe_exp(symbol))
         if (selected := config.get(CONF_SELECTED_INDEX)) is not None:
             value = await lv_int.process(selected)
             lv_add(w.var.set_selected_index(value, literal("LV_ANIM_OFF")))
diff --git a/esphome/components/mapping/mapping.h b/esphome/components/mapping/mapping.h
index 99c1f38829..2b8f0d39b2 100644
--- a/esphome/components/mapping/mapping.h
+++ b/esphome/components/mapping/mapping.h
@@ -2,6 +2,7 @@
 
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
+#include <cinttypes>
 #include <map>
 #include <string>
 
@@ -43,8 +44,17 @@ template<typename K, typename V> class Mapping {
       esph_log_e(TAG, "Key '%p' not found in mapping", key);
     } else if constexpr (std::is_same_v<K, std::string>) {
       esph_log_e(TAG, "Key '%s' not found in mapping", key.c_str());
+    } else if constexpr (std::is_integral_v<K>) {
+      char buf[24];  // enough for 64-bit integer
+      if constexpr (std::is_unsigned_v<K>) {
+        buf_append_printf(buf, sizeof(buf), 0, "%" PRIu64, static_cast<uint64_t>(key));
+      } else {
+        buf_append_printf(buf, sizeof(buf), 0, "%" PRId64, static_cast<int64_t>(key));
+      }
+      esph_log_e(TAG, "Key '%s' not found in mapping", buf);
     } else {
-      esph_log_e(TAG, "Key '%s' not found in mapping", to_string(key).c_str());
+      // All supported key types are handled above - this should never be reached
+      static_assert(sizeof(K) == 0, "Unsupported key type for Mapping error logging");
     }
     return {};
   }
diff --git a/esphome/components/max6956/max6956.cpp b/esphome/components/max6956/max6956.cpp
index 13fe5a5323..6ba17f11d1 100644
--- a/esphome/components/max6956/max6956.cpp
+++ b/esphome/components/max6956/max6956.cpp
@@ -162,7 +162,7 @@ void MAX6956GPIOPin::pin_mode(gpio::Flags flags) { this->parent_->pin_mode(this-
 bool MAX6956GPIOPin::digital_read() { return this->parent_->digital_read(this->pin_) != this->inverted_; }
 void MAX6956GPIOPin::digital_write(bool value) { this->parent_->digital_write(this->pin_, value != this->inverted_); }
 size_t MAX6956GPIOPin::dump_summary(char *buffer, size_t len) const {
-  return snprintf(buffer, len, "%u via Max6956", this->pin_);
+  return buf_append_printf(buffer, len, 0, "%u via Max6956", this->pin_);
 }
 
 }  // namespace max6956
diff --git a/esphome/components/max7219/display.py b/esphome/components/max7219/display.py
index c9d10f3c45..a434125148 100644
--- a/esphome/components/max7219/display.py
+++ b/esphome/components/max7219/display.py
@@ -29,7 +29,7 @@ CONFIG_SCHEMA = (
 
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
     await display.register_display(var, config)
 
     cg.add(var.set_num_chips(config[CONF_NUM_CHIPS]))
diff --git a/esphome/components/max7219digit/display.py b/esphome/components/max7219digit/display.py
index fef121ff10..e6d53efc5d 100644
--- a/esphome/components/max7219digit/display.py
+++ b/esphome/components/max7219digit/display.py
@@ -86,7 +86,7 @@ CONFIG_SCHEMA = (
 
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
     await display.register_display(var, config)
 
     cg.add(var.set_num_chips(config[CONF_NUM_CHIPS]))
diff --git a/esphome/components/mcp23016/mcp23016.cpp b/esphome/components/mcp23016/mcp23016.cpp
index 87c2668962..56b2ecf9f4 100644
--- a/esphome/components/mcp23016/mcp23016.cpp
+++ b/esphome/components/mcp23016/mcp23016.cpp
@@ -100,7 +100,7 @@ void MCP23016GPIOPin::pin_mode(gpio::Flags flags) { this->parent_->pin_mode(this
 bool MCP23016GPIOPin::digital_read() { return this->parent_->digital_read(this->pin_) != this->inverted_; }
 void MCP23016GPIOPin::digital_write(bool value) { this->parent_->digital_write(this->pin_, value != this->inverted_); }
 size_t MCP23016GPIOPin::dump_summary(char *buffer, size_t len) const {
-  return snprintf(buffer, len, "%u via MCP23016", this->pin_);
+  return buf_append_printf(buffer, len, 0, "%u via MCP23016", this->pin_);
 }
 
 }  // namespace mcp23016
diff --git a/esphome/components/mcp23xxx_base/mcp23xxx_base.cpp b/esphome/components/mcp23xxx_base/mcp23xxx_base.cpp
index 302f6b8280..535119fc5c 100644
--- a/esphome/components/mcp23xxx_base/mcp23xxx_base.cpp
+++ b/esphome/components/mcp23xxx_base/mcp23xxx_base.cpp
@@ -17,7 +17,7 @@ template<uint8_t N> void MCP23XXXGPIOPin<N>::digital_write(bool value) {
   this->parent_->digital_write(this->pin_, value != this->inverted_);
 }
 template<uint8_t N> size_t MCP23XXXGPIOPin<N>::dump_summary(char *buffer, size_t len) const {
-  return snprintf(buffer, len, "%u via MCP23XXX", this->pin_);
+  return buf_append_printf(buffer, len, 0, "%u via MCP23XXX", this->pin_);
 }
 
 template class MCP23XXXGPIOPin<8>;
diff --git a/esphome/components/mdns/mdns_esp32.cpp b/esphome/components/mdns/mdns_esp32.cpp
index e6b43e59cb..3123f3b604 100644
--- a/esphome/components/mdns/mdns_esp32.cpp
+++ b/esphome/components/mdns/mdns_esp32.cpp
@@ -24,13 +24,14 @@ static void register_esp32(MDNSComponent *comp, StaticVector<MDNSService, MDNS_S
   mdns_instance_name_set(hostname);
 
   for (const auto &service : services) {
-    auto txt_records = std::make_unique<mdns_txt_item_t[]>(service.txt_records.size());
+    // Stack buffer for up to 16 txt records, heap fallback for more
+    SmallBufferWithHeapFallback<16, mdns_txt_item_t> txt_records(service.txt_records.size());
     for (size_t i = 0; i < service.txt_records.size(); i++) {
       const auto &record = service.txt_records[i];
       // key and value are either compile-time string literals in flash or pointers to dynamic_txt_values_
       // Both remain valid for the lifetime of this function, and ESP-IDF makes internal copies
-      txt_records[i].key = MDNS_STR_ARG(record.key);
-      txt_records[i].value = MDNS_STR_ARG(record.value);
+      txt_records.get()[i].key = MDNS_STR_ARG(record.key);
+      txt_records.get()[i].value = MDNS_STR_ARG(record.value);
     }
     uint16_t port = const_cast<TemplatableValue<uint16_t> &>(service.port).value();
     err = mdns_service_add(nullptr, MDNS_STR_ARG(service.service_type), MDNS_STR_ARG(service.proto), port,
diff --git a/esphome/components/mhz19/sensor.py b/esphome/components/mhz19/sensor.py
index 1f698be404..2841afde7a 100644
--- a/esphome/components/mhz19/sensor.py
+++ b/esphome/components/mhz19/sensor.py
@@ -7,6 +7,7 @@ from esphome.const import (
     CONF_CO2,
     CONF_ID,
     CONF_TEMPERATURE,
+    CONF_WARMUP_TIME,
     DEVICE_CLASS_CARBON_DIOXIDE,
     DEVICE_CLASS_TEMPERATURE,
     ICON_MOLECULE_CO2,
@@ -18,7 +19,6 @@ from esphome.const import (
 DEPENDENCIES = ["uart"]
 
 CONF_AUTOMATIC_BASELINE_CALIBRATION = "automatic_baseline_calibration"
-CONF_WARMUP_TIME = "warmup_time"
 CONF_DETECTION_RANGE = "detection_range"
 
 mhz19_ns = cg.esphome_ns.namespace("mhz19")
diff --git a/esphome/components/mipi_rgb/display.py b/esphome/components/mipi_rgb/display.py
index 96e167b2e6..084fe6de14 100644
--- a/esphome/components/mipi_rgb/display.py
+++ b/esphome/components/mipi_rgb/display.py
@@ -260,7 +260,7 @@ async def to_code(config):
         cg.add(var.set_enable_pins(enable))
 
     if CONF_SPI_ID in config:
-        await spi.register_spi_device(var, config)
+        await spi.register_spi_device(var, config, write_only=True)
         sequence, madctl = model.get_sequence(config)
         cg.add(var.set_init_sequence(sequence))
         cg.add(var.set_madctl(madctl))
diff --git a/esphome/components/mipi_spi/display.py b/esphome/components/mipi_spi/display.py
index 69bf133c68..8dccfa3a92 100644
--- a/esphome/components/mipi_spi/display.py
+++ b/esphome/components/mipi_spi/display.py
@@ -443,6 +443,4 @@ async def to_code(config):
         )
         cg.add(var.set_writer(lambda_))
     await display.register_display(var, config)
-    await spi.register_spi_device(var, config)
-    # Displays are write-only, set the SPI device to write-only as well
-    cg.add(var.set_write_only(True))
+    await spi.register_spi_device(var, config, write_only=True)
diff --git a/esphome/components/mipi_spi/mipi_spi.h b/esphome/components/mipi_spi/mipi_spi.h
index a59cb8104b..fd5bc97596 100644
--- a/esphome/components/mipi_spi/mipi_spi.h
+++ b/esphome/components/mipi_spi/mipi_spi.h
@@ -224,12 +224,9 @@ class MipiSpi : public display::Display,
                     this->madctl_ & MADCTL_BGR ? "BGR" : "RGB", DISPLAYPIXEL * 8, IS_BIG_ENDIAN ? "Big" : "Little");
     if (this->brightness_.has_value())
       esph_log_config(TAG, "  Brightness: %u", this->brightness_.value());
-    if (this->cs_ != nullptr)
-      esph_log_config(TAG, "  CS Pin: %s", this->cs_->dump_summary().c_str());
-    if (this->reset_pin_ != nullptr)
-      esph_log_config(TAG, "  Reset Pin: %s", this->reset_pin_->dump_summary().c_str());
-    if (this->dc_pin_ != nullptr)
-      esph_log_config(TAG, "  DC Pin: %s", this->dc_pin_->dump_summary().c_str());
+    log_pin(TAG, "  CS Pin: ", this->cs_);
+    log_pin(TAG, "  Reset Pin: ", this->reset_pin_);
+    log_pin(TAG, "  DC Pin: ", this->dc_pin_);
     esph_log_config(TAG,
                     "  SPI Mode: %d\n"
                     "  SPI Data rate: %dMHz\n"
diff --git a/esphome/components/mipi_spi/models/adafruit.py b/esphome/components/mipi_spi/models/adafruit.py
index 0e91107bee..26790b1493 100644
--- a/esphome/components/mipi_spi/models/adafruit.py
+++ b/esphome/components/mipi_spi/models/adafruit.py
@@ -26,5 +26,3 @@ ST7789V.extend(
     reset_pin=40,
     invert_colors=True,
 )
-
-models = {}
diff --git a/esphome/components/mipi_spi/models/amoled.py b/esphome/components/mipi_spi/models/amoled.py
index 4d6c8da4b0..32cad70ac0 100644
--- a/esphome/components/mipi_spi/models/amoled.py
+++ b/esphome/components/mipi_spi/models/amoled.py
@@ -105,6 +105,3 @@ CO5300 = DriverChip(
         (WCE, 0x00),
     ),
 )
-
-
-models = {}
diff --git a/esphome/components/mipi_spi/models/cyd.py b/esphome/components/mipi_spi/models/cyd.py
index a25ecf33a8..7229412f18 100644
--- a/esphome/components/mipi_spi/models/cyd.py
+++ b/esphome/components/mipi_spi/models/cyd.py
@@ -1,10 +1,45 @@
-from .ili import ILI9341
+from .ili import ILI9341, ILI9342, ST7789V
 
 ILI9341.extend(
+    # ESP32-2432S028 CYD board with Micro USB, has ILI9341 controller
     "ESP32-2432S028",
     data_rate="40MHz",
-    cs_pin=15,
-    dc_pin=2,
+    cs_pin={"number": 15, "ignore_strapping_warning": True},
+    dc_pin={"number": 2, "ignore_strapping_warning": True},
 )
 
-models = {}
+ST7789V.extend(
+    # ESP32-2432S028 CYD board with USB C + Micro USB, has ST7789V controller
+    "ESP32-2432S028-7789",
+    data_rate="40MHz",
+    cs_pin={"number": 15, "ignore_strapping_warning": True},
+    dc_pin={"number": 2, "ignore_strapping_warning": True},
+)
+
+# fmt: off
+
+ILI9342.extend(
+    # ESP32-2432S028 CYD board with USB C + Micro USB, has ILI9342 controller
+    "ESP32-2432S028-9342",
+    data_rate="40MHz",
+    cs_pin={"number": 15, "ignore_strapping_warning": True},
+    dc_pin={"number": 2, "ignore_strapping_warning": True},
+    initsequence=(
+        (0xCB, 0x39, 0x2C, 0x00, 0x34, 0x02),  # Power Control A
+        (0xCF, 0x00, 0xC1, 0x30),  # Power Control B
+        (0xE8, 0x85, 0x00, 0x78),  # Driver timing control A
+        (0xEA, 0x00, 0x00),  # Driver timing control B
+        (0xED, 0x64, 0x03, 0x12, 0x81),  # Power on sequence control
+        (0xF7, 0x20),  # Pump ratio control
+        (0xC0, 0x23),  # Power Control 1
+        (0xC1, 0x10),  # Power Control 2
+        (0xC5, 0x3E, 0x28),  # VCOM Control 1
+        (0xC7, 0x86),  # VCOM Control 2
+        (0xB1, 0x00, 0x1B),  # Frame Rate Control
+        (0xB6, 0x0A, 0xA2, 0x27, 0x00),  # Display Function Control
+        (0xF2, 0x00),  # Enable 3G
+        (0x26, 0x01),  # Gamma Set
+        (0xE0, 0x00, 0x0C, 0x11, 0x04, 0x11, 0x08, 0x37, 0x89, 0x4C, 0x06, 0x0C, 0x0A, 0x2E, 0x34, 0x0F),  # Positive Gamma Correction
+        (0xE1, 0x00, 0x0B, 0x11, 0x05, 0x13, 0x09, 0x33, 0x67, 0x48, 0x07, 0x0E, 0x0B, 0x23, 0x33, 0x0F),  # Negative Gamma Correction
+    )
+)
diff --git a/esphome/components/mipi_spi/models/ili.py b/esphome/components/mipi_spi/models/ili.py
index 60a25c32a9..6b672b0859 100644
--- a/esphome/components/mipi_spi/models/ili.py
+++ b/esphome/components/mipi_spi/models/ili.py
@@ -148,6 +148,34 @@ ILI9341 = DriverChip(
         ),
     ),
 )
+
+# fmt: off
+
+ILI9342 = DriverChip(
+    "ILI9342",
+    width=320,
+    height=240,
+    mirror_x=True,
+    initsequence=(
+        (0xCB, 0x39, 0x2C, 0x00, 0x34, 0x02),  # Power Control A
+        (0xCF, 0x00, 0xC1, 0x30),  # Power Control B
+        (0xE8, 0x85, 0x00, 0x78),  # Driver timing control A
+        (0xEA, 0x00, 0x00),  # Driver timing control B
+        (0xED, 0x64, 0x03, 0x12, 0x81),  # Power on sequence control
+        (0xF7, 0x20),  # Pump ratio control
+        (0xC0, 0x23),  # Power Control 1
+        (0xC1, 0x10),  # Power Control 2
+        (0xC5, 0x3E, 0x28),  # VCOM Control 1
+        (0xC7, 0x86),  # VCOM Control 2
+        (0xB1, 0x00, 0x1B),  # Frame Rate Control
+        (0xB6, 0x0A, 0xA2, 0x27, 0x00),  # Display Function Control
+        (0xF2, 0x00),  # Enable 3G
+        (0x26, 0x01),  # Gamma Set
+        (0xE0, 0x0F, 0x1F, 0x1C, 0x0C, 0x0F, 0x08, 0x48, 0x98, 0x37, 0x0A, 0x13, 0x04, 0x11, 0x0D, 0x00),  # Positive Gamma
+        (0xE1, 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75, 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00),  # Negative Gamma
+    ),
+)
+
 # M5Stack Core2 uses ILI9341 chip - mirror_x disabled for correct orientation
 ILI9341.extend(
     "M5CORE2",
@@ -758,5 +786,3 @@ ST7796.extend(
     dc_pin=0,
     invert_colors=True,
 )
-
-models = {}
diff --git a/esphome/components/mipi_spi/models/jc.py b/esphome/components/mipi_spi/models/jc.py
index 5b936fd956..854814f572 100644
--- a/esphome/components/mipi_spi/models/jc.py
+++ b/esphome/components/mipi_spi/models/jc.py
@@ -588,5 +588,3 @@ DriverChip(
         (0x29, 0x00),
     ),
 )
-
-models = {}
diff --git a/esphome/components/mipi_spi/models/lanbon.py b/esphome/components/mipi_spi/models/lanbon.py
index 6f9aa58674..8cec3c8317 100644
--- a/esphome/components/mipi_spi/models/lanbon.py
+++ b/esphome/components/mipi_spi/models/lanbon.py
@@ -11,5 +11,3 @@ ST7789V.extend(
     dc_pin=21,
     reset_pin=18,
 )
-
-models = {}
diff --git a/esphome/components/mipi_spi/models/lilygo.py b/esphome/components/mipi_spi/models/lilygo.py
index 13ddc67465..46ec809029 100644
--- a/esphome/components/mipi_spi/models/lilygo.py
+++ b/esphome/components/mipi_spi/models/lilygo.py
@@ -56,5 +56,3 @@ ST7796.extend(
     backlight_pin=48,
     invert_colors=True,
 )
-
-models = {}
diff --git a/esphome/components/modbus_controller/modbus_controller.h b/esphome/components/modbus_controller/modbus_controller.h
index 6ed05715cb..fca2926568 100644
--- a/esphome/components/modbus_controller/modbus_controller.h
+++ b/esphome/components/modbus_controller/modbus_controller.h
@@ -271,24 +271,31 @@ class ServerRegister {
 
   // Formats a raw value into a string representation based on the value type for debugging
   std::string format_value(int64_t value) const {
+    // max 44: float with %.1f can be up to 42 chars (3.4e38 → 39 integer digits + sign + decimal + 1 digit)
+    // plus null terminator = 43, rounded to 44 for 4-byte alignment
+    char buf[44];
     switch (this->value_type) {
       case SensorValueType::U_WORD:
       case SensorValueType::U_DWORD:
       case SensorValueType::U_DWORD_R:
       case SensorValueType::U_QWORD:
       case SensorValueType::U_QWORD_R:
-        return std::to_string(static_cast<uint64_t>(value));
+        buf_append_printf(buf, sizeof(buf), 0, "%" PRIu64, static_cast<uint64_t>(value));
+        return buf;
       case SensorValueType::S_WORD:
       case SensorValueType::S_DWORD:
       case SensorValueType::S_DWORD_R:
       case SensorValueType::S_QWORD:
       case SensorValueType::S_QWORD_R:
-        return std::to_string(value);
+        buf_append_printf(buf, sizeof(buf), 0, "%" PRId64, value);
+        return buf;
       case SensorValueType::FP32_R:
       case SensorValueType::FP32:
-        return str_sprintf("%.1f", bit_cast<float>(static_cast<uint32_t>(value)));
+        buf_append_printf(buf, sizeof(buf), 0, "%.1f", bit_cast<float>(static_cast<uint32_t>(value)));
+        return buf;
       default:
-        return std::to_string(value);
+        buf_append_printf(buf, sizeof(buf), 0, "%" PRId64, value);
+        return buf;
     }
   }
 
diff --git a/esphome/components/modbus_controller/text_sensor/modbus_textsensor.cpp b/esphome/components/modbus_controller/text_sensor/modbus_textsensor.cpp
index 89e86741b0..b26411b72e 100644
--- a/esphome/components/modbus_controller/text_sensor/modbus_textsensor.cpp
+++ b/esphome/components/modbus_controller/text_sensor/modbus_textsensor.cpp
@@ -16,12 +16,20 @@ void ModbusTextSensor::parse_and_publish(const std::vector<uint8_t> &data) {
   while ((items_left > 0) && index < data.size()) {
     uint8_t b = data[index];
     switch (this->encode_) {
-      case RawEncoding::HEXBYTES:
-        output_str += str_snprintf("%02x", 2, b);
+      case RawEncoding::HEXBYTES: {
+        // max 3: 2 hex digits + null
+        char hex_buf[3];
+        snprintf(hex_buf, sizeof(hex_buf), "%02x", b);
+        output_str += hex_buf;
         break;
-      case RawEncoding::COMMA:
-        output_str += str_sprintf(index != this->offset ? ",%d" : "%d", b);
+      }
+      case RawEncoding::COMMA: {
+        // max 5: optional ','(1) + uint8(3) + null, for both ",%d" and "%d"
+        char dec_buf[5];
+        snprintf(dec_buf, sizeof(dec_buf), index != this->offset ? ",%d" : "%d", b);
+        output_str += dec_buf;
         break;
+      }
       case RawEncoding::ANSI:
         if (b < 0x20)
           break;
diff --git a/esphome/components/mpr121/mpr121.cpp b/esphome/components/mpr121/mpr121.cpp
index 4b358e384c..cd9c81fe03 100644
--- a/esphome/components/mpr121/mpr121.cpp
+++ b/esphome/components/mpr121/mpr121.cpp
@@ -154,7 +154,7 @@ void MPR121GPIOPin::digital_write(bool value) {
 }
 
 size_t MPR121GPIOPin::dump_summary(char *buffer, size_t len) const {
-  return snprintf(buffer, len, "ELE%u on MPR121", this->pin_);
+  return buf_append_printf(buffer, len, 0, "ELE%u on MPR121", this->pin_);
 }
 
 }  // namespace mpr121
diff --git a/esphome/components/mqtt/custom_mqtt_device.cpp b/esphome/components/mqtt/custom_mqtt_device.cpp
index 7ff65bb42c..64521f5cf3 100644
--- a/esphome/components/mqtt/custom_mqtt_device.cpp
+++ b/esphome/components/mqtt/custom_mqtt_device.cpp
@@ -18,7 +18,7 @@ bool CustomMQTTDevice::publish(const std::string &topic, float value, int8_t num
 }
 bool CustomMQTTDevice::publish(const std::string &topic, int value) {
   char buffer[24];
-  int len = snprintf(buffer, sizeof(buffer), "%d", value);
+  size_t len = buf_append_printf(buffer, sizeof(buffer), 0, "%d", value);
   return global_mqtt_client->publish(topic, buffer, len);
 }
 bool CustomMQTTDevice::publish_json(const std::string &topic, const json::json_build_t &f, uint8_t qos, bool retain) {
diff --git a/esphome/components/mqtt/mqtt_alarm_control_panel.cpp b/esphome/components/mqtt/mqtt_alarm_control_panel.cpp
index 6245d10882..715e6feed8 100644
--- a/esphome/components/mqtt/mqtt_alarm_control_panel.cpp
+++ b/esphome/components/mqtt/mqtt_alarm_control_panel.cpp
@@ -43,7 +43,7 @@ void MQTTAlarmControlPanelComponent::setup() {
 
 void MQTTAlarmControlPanelComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT alarm_control_panel '%s':", this->alarm_control_panel_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, true)
+  LOG_MQTT_COMPONENT(true, true);
   ESP_LOGCONFIG(TAG,
                 "  Supported Features: %" PRIu32 "\n"
                 "  Requires Code to Disarm: %s\n"
diff --git a/esphome/components/mqtt/mqtt_binary_sensor.cpp b/esphome/components/mqtt/mqtt_binary_sensor.cpp
index a37043406b..7cbb5dcc0e 100644
--- a/esphome/components/mqtt/mqtt_binary_sensor.cpp
+++ b/esphome/components/mqtt/mqtt_binary_sensor.cpp
@@ -19,7 +19,7 @@ void MQTTBinarySensorComponent::setup() {
 
 void MQTTBinarySensorComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT Binary Sensor '%s':", this->binary_sensor_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, false)
+  LOG_MQTT_COMPONENT(true, false);
 }
 MQTTBinarySensorComponent::MQTTBinarySensorComponent(binary_sensor::BinarySensor *binary_sensor)
     : binary_sensor_(binary_sensor) {
diff --git a/esphome/components/mqtt/mqtt_client.cpp b/esphome/components/mqtt/mqtt_client.cpp
index 0ab5b238b5..e7364f3406 100644
--- a/esphome/components/mqtt/mqtt_client.cpp
+++ b/esphome/components/mqtt/mqtt_client.cpp
@@ -5,6 +5,7 @@
 #include <utility>
 #include "esphome/components/network/util.h"
 #include "esphome/core/application.h"
+#include "esphome/core/entity_base.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 #include "esphome/core/version.h"
@@ -66,10 +67,13 @@ void MQTTClientComponent::setup() {
         "esphome/discover", [this](const std::string &topic, const std::string &payload) { this->send_device_info_(); },
         2);
 
-    std::string topic = "esphome/ping/";
-    topic.append(App.get_name());
+    // Format topic on stack - subscribe() copies it
+    // "esphome/ping/" (13) + name (ESPHOME_DEVICE_NAME_MAX_LEN) + null (1)
+    constexpr size_t ping_topic_buffer_size = 13 + ESPHOME_DEVICE_NAME_MAX_LEN + 1;
+    char ping_topic[ping_topic_buffer_size];
+    buf_append_printf(ping_topic, sizeof(ping_topic), 0, "esphome/ping/%s", App.get_name().c_str());
     this->subscribe(
-        topic, [this](const std::string &topic, const std::string &payload) { this->send_device_info_(); }, 2);
+        ping_topic, [this](const std::string &topic, const std::string &payload) { this->send_device_info_(); }, 2);
   }
 
   if (this->enable_on_boot_) {
@@ -81,8 +85,11 @@ void MQTTClientComponent::send_device_info_() {
   if (!this->is_connected() or !this->is_discovery_ip_enabled()) {
     return;
   }
-  std::string topic = "esphome/discover/";
-  topic.append(App.get_name());
+  // Format topic on stack to avoid heap allocation
+  // "esphome/discover/" (17) + name (ESPHOME_DEVICE_NAME_MAX_LEN) + null (1)
+  constexpr size_t topic_buffer_size = 17 + ESPHOME_DEVICE_NAME_MAX_LEN + 1;
+  char topic[topic_buffer_size];
+  buf_append_printf(topic, sizeof(topic), 0, "esphome/discover/%s", App.get_name().c_str());
 
   // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   this->publish_json(
@@ -91,7 +98,17 @@ void MQTTClientComponent::send_device_info_() {
         uint8_t index = 0;
         for (auto &ip : network::get_ip_addresses()) {
           if (ip.is_set()) {
-            root["ip" + (index == 0 ? "" : esphome::to_string(index))] = ip.str();
+            char key[8];  // "ip" + up to 3 digits + null
+            char ip_buf[network::IP_ADDRESS_BUFFER_SIZE];
+            if (index == 0) {
+              key[0] = 'i';
+              key[1] = 'p';
+              key[2] = '\0';
+            } else {
+              buf_append_printf(key, sizeof(key), 0, "ip%u", index);
+            }
+            ip.str_to(ip_buf);
+            root[key] = ip_buf;
             index++;
           }
         }
@@ -396,6 +413,12 @@ void MQTTClientComponent::loop() {
 
         this->last_connected_ = now;
         this->resubscribe_subscriptions_();
+
+        // Process pending resends for all MQTT components centrally
+        // This is more efficient than each component polling in its own loop
+        for (MQTTComponent *component : this->children_) {
+          component->process_resend();
+        }
       }
       break;
   }
@@ -500,39 +523,49 @@ bool MQTTClientComponent::publish(const std::string &topic, const std::string &p
 
 bool MQTTClientComponent::publish(const std::string &topic, const char *payload, size_t payload_length, uint8_t qos,
                                   bool retain) {
-  return publish({.topic = topic, .payload = std::string(payload, payload_length), .qos = qos, .retain = retain});
+  return this->publish(topic.c_str(), payload, payload_length, qos, retain);
 }
 
 bool MQTTClientComponent::publish(const MQTTMessage &message) {
+  return this->publish(message.topic.c_str(), message.payload.c_str(), message.payload.length(), message.qos,
+                       message.retain);
+}
+bool MQTTClientComponent::publish_json(const std::string &topic, const json::json_build_t &f, uint8_t qos,
+                                       bool retain) {
+  return this->publish_json(topic.c_str(), f, qos, retain);
+}
+
+bool MQTTClientComponent::publish(const char *topic, const char *payload, size_t payload_length, uint8_t qos,
+                                  bool retain) {
   if (!this->is_connected()) {
-    // critical components will re-transmit their messages
     return false;
   }
-  bool logging_topic = this->log_message_.topic == message.topic;
-  bool ret = this->mqtt_backend_.publish(message);
+  size_t topic_len = strlen(topic);
+  bool logging_topic = (topic_len == this->log_message_.topic.size()) &&
+                       (memcmp(this->log_message_.topic.c_str(), topic, topic_len) == 0);
+  bool ret = this->mqtt_backend_.publish(topic, payload, payload_length, qos, retain);
   delay(0);
   if (!ret && !logging_topic && this->is_connected()) {
     delay(0);
-    ret = this->mqtt_backend_.publish(message);
+    ret = this->mqtt_backend_.publish(topic, payload, payload_length, qos, retain);
     delay(0);
   }
 
   if (!logging_topic) {
     if (ret) {
-      ESP_LOGV(TAG, "Publish(topic='%s' payload='%s' retain=%d qos=%d)", message.topic.c_str(), message.payload.c_str(),
-               message.retain, message.qos);
+      ESP_LOGV(TAG, "Publish(topic='%s' retain=%d qos=%d)", topic, retain, qos);
+      ESP_LOGVV(TAG, "Publish payload (len=%u): '%.*s'", payload_length, static_cast<int>(payload_length), payload);
     } else {
-      ESP_LOGV(TAG, "Publish failed for topic='%s' (len=%u). Will retry", message.topic.c_str(),
-               message.payload.length());
+      ESP_LOGV(TAG, "Publish failed for topic='%s' (len=%u). Will retry", topic, payload_length);
       this->status_momentary_warning("publish", 1000);
     }
   }
   return ret != 0;
 }
-bool MQTTClientComponent::publish_json(const std::string &topic, const json::json_build_t &f, uint8_t qos,
-                                       bool retain) {
+
+bool MQTTClientComponent::publish_json(const char *topic, const json::json_build_t &f, uint8_t qos, bool retain) {
   std::string message = json::build_json(f);
-  return this->publish(topic, message, qos, retain);
+  return this->publish(topic, message.c_str(), message.length(), qos, retain);
 }
 
 void MQTTClientComponent::enable() {
@@ -610,18 +643,10 @@ static bool topic_match(const char *message, const char *subscription) {
 }
 
 void MQTTClientComponent::on_message(const std::string &topic, const std::string &payload) {
-#ifdef USE_ESP8266
-  // on ESP8266, this is called in lwIP/AsyncTCP task; some components do not like running
-  // from a different task.
-  this->defer([this, topic, payload]() {
-#endif
-    for (auto &subscription : this->subscriptions_) {
-      if (topic_match(topic.c_str(), subscription.topic.c_str()))
-        subscription.callback(topic, payload);
-    }
-#ifdef USE_ESP8266
-  });
-#endif
+  for (auto &subscription : this->subscriptions_) {
+    if (topic_match(topic.c_str(), subscription.topic.c_str()))
+      subscription.callback(topic, payload);
+  }
 }
 
 // Setters
@@ -635,7 +660,8 @@ void MQTTClientComponent::set_log_message_template(MQTTMessage &&message) { this
 const MQTTDiscoveryInfo &MQTTClientComponent::get_discovery_info() const { return this->discovery_info_; }
 void MQTTClientComponent::set_topic_prefix(const std::string &topic_prefix, const std::string &check_topic_prefix) {
   if (App.is_name_add_mac_suffix_enabled() && (topic_prefix == check_topic_prefix)) {
-    this->topic_prefix_ = str_sanitize(App.get_name());
+    char buf[ESPHOME_DEVICE_NAME_MAX_LEN + 1];
+    this->topic_prefix_ = str_sanitize_to(buf, App.get_name().c_str());
   } else {
     this->topic_prefix_ = topic_prefix;
   }
diff --git a/esphome/components/mqtt/mqtt_client.h b/esphome/components/mqtt/mqtt_client.h
index 9e9db03b19..38bc0b4da3 100644
--- a/esphome/components/mqtt/mqtt_client.h
+++ b/esphome/components/mqtt/mqtt_client.h
@@ -229,6 +229,9 @@ class MQTTClientComponent : public Component
   bool publish(const std::string &topic, const char *payload, size_t payload_length, uint8_t qos = 0,
                bool retain = false);
 
+  /// Publish directly without creating MQTTMessage (avoids heap allocation for topic)
+  bool publish(const char *topic, const char *payload, size_t payload_length, uint8_t qos = 0, bool retain = false);
+
   /** Construct and send a JSON MQTT message.
    *
    * @param topic The topic.
@@ -237,6 +240,9 @@ class MQTTClientComponent : public Component
    */
   bool publish_json(const std::string &topic, const json::json_build_t &f, uint8_t qos = 0, bool retain = false);
 
+  /// Publish JSON directly without heap allocation for topic
+  bool publish_json(const char *topic, const json::json_build_t &f, uint8_t qos = 0, bool retain = false);
+
   /// Setup the MQTT client, registering a bunch of callbacks and attempting to connect.
   void setup() override;
   void dump_config() override;
diff --git a/esphome/components/mqtt/mqtt_component.cpp b/esphome/components/mqtt/mqtt_component.cpp
index 8e4b3437ab..7607a4e817 100644
--- a/esphome/components/mqtt/mqtt_component.cpp
+++ b/esphome/components/mqtt/mqtt_component.cpp
@@ -27,20 +27,23 @@ inline char *append_char(char *p, char c) {
 // Max lengths for stack-based topic building.
 // These limits are enforced at Python config validation time in mqtt/__init__.py
 // using cv.Length() validators for topic_prefix and discovery_prefix.
-// MQTT_COMPONENT_TYPE_MAX_LEN and MQTT_SUFFIX_MAX_LEN are defined in mqtt_component.h.
+// MQTT_COMPONENT_TYPE_MAX_LEN, MQTT_SUFFIX_MAX_LEN, and MQTT_DEFAULT_TOPIC_MAX_LEN are in mqtt_component.h.
 // ESPHOME_DEVICE_NAME_MAX_LEN and OBJECT_ID_MAX_LEN are defined in entity_base.h.
 // This ensures the stack buffers below are always large enough.
-static constexpr size_t TOPIC_PREFIX_MAX_LEN = 64;      // Validated in Python: cv.Length(max=64)
 static constexpr size_t DISCOVERY_PREFIX_MAX_LEN = 64;  // Validated in Python: cv.Length(max=64)
-
-// Stack buffer sizes - safe because all inputs are length-validated at config time
-// Format: prefix + "/" + type + "/" + object_id + "/" + suffix + null
-static constexpr size_t DEFAULT_TOPIC_MAX_LEN =
-    TOPIC_PREFIX_MAX_LEN + 1 + MQTT_COMPONENT_TYPE_MAX_LEN + 1 + OBJECT_ID_MAX_LEN + 1 + MQTT_SUFFIX_MAX_LEN + 1;
 // Format: prefix + "/" + type + "/" + name + "/" + object_id + "/config" + null
 static constexpr size_t DISCOVERY_TOPIC_MAX_LEN = DISCOVERY_PREFIX_MAX_LEN + 1 + MQTT_COMPONENT_TYPE_MAX_LEN + 1 +
                                                   ESPHOME_DEVICE_NAME_MAX_LEN + 1 + OBJECT_ID_MAX_LEN + 7 + 1;
 
+// Function implementation of LOG_MQTT_COMPONENT macro to reduce code size
+void log_mqtt_component(const char *tag, MQTTComponent *obj, bool state_topic, bool command_topic) {
+  char buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  if (state_topic)
+    ESP_LOGCONFIG(tag, "  State Topic: '%s'", obj->get_state_topic_to_(buf).c_str());
+  if (command_topic)
+    ESP_LOGCONFIG(tag, "  Command Topic: '%s'", obj->get_command_topic_to_(buf).c_str());
+}
+
 void MQTTComponent::set_qos(uint8_t qos) { this->qos_ = qos; }
 
 void MQTTComponent::set_subscribe_qos(uint8_t qos) { this->subscribe_qos_ = qos; }
@@ -48,7 +51,8 @@ void MQTTComponent::set_subscribe_qos(uint8_t qos) { this->subscribe_qos_ = qos;
 void MQTTComponent::set_retain(bool retain) { this->retain_ = retain; }
 
 std::string MQTTComponent::get_discovery_topic_(const MQTTDiscoveryInfo &discovery_info) const {
-  std::string sanitized_name = str_sanitize(App.get_name());
+  char sanitized_name[ESPHOME_DEVICE_NAME_MAX_LEN + 1];
+  str_sanitize_to(sanitized_name, App.get_name().c_str());
   const char *comp_type = this->component_type();
   char object_id_buf[OBJECT_ID_MAX_LEN];
   StringRef object_id = this->get_default_object_id_to_(object_id_buf);
@@ -60,7 +64,7 @@ std::string MQTTComponent::get_discovery_topic_(const MQTTDiscoveryInfo &discove
   p = append_char(p, '/');
   p = append_str(p, comp_type, strlen(comp_type));
   p = append_char(p, '/');
-  p = append_str(p, sanitized_name.data(), sanitized_name.size());
+  p = append_str(p, sanitized_name, strlen(sanitized_name));
   p = append_char(p, '/');
   p = append_str(p, object_id.c_str(), object_id.size());
   p = append_str(p, "/config", 7);
@@ -68,19 +72,18 @@ std::string MQTTComponent::get_discovery_topic_(const MQTTDiscoveryInfo &discove
   return std::string(buf, p - buf);
 }
 
-std::string MQTTComponent::get_default_topic_for_(const std::string &suffix) const {
+StringRef MQTTComponent::get_default_topic_for_to_(std::span<char, MQTT_DEFAULT_TOPIC_MAX_LEN> buf, const char *suffix,
+                                                   size_t suffix_len) const {
   const std::string &topic_prefix = global_mqtt_client->get_topic_prefix();
   if (topic_prefix.empty()) {
-    // If the topic_prefix is null, the default topic should be null
-    return "";
+    return StringRef();  // Empty topic_prefix means no default topic
   }
 
   const char *comp_type = this->component_type();
   char object_id_buf[OBJECT_ID_MAX_LEN];
   StringRef object_id = this->get_default_object_id_to_(object_id_buf);
 
-  char buf[DEFAULT_TOPIC_MAX_LEN];
-  char *p = buf;
+  char *p = buf.data();
 
   p = append_str(p, topic_prefix.data(), topic_prefix.size());
   p = append_char(p, '/');
@@ -88,21 +91,44 @@ std::string MQTTComponent::get_default_topic_for_(const std::string &suffix) con
   p = append_char(p, '/');
   p = append_str(p, object_id.c_str(), object_id.size());
   p = append_char(p, '/');
-  p = append_str(p, suffix.data(), suffix.size());
+  p = append_str(p, suffix, suffix_len);
+  *p = '\0';
 
-  return std::string(buf, p - buf);
+  return StringRef(buf.data(), p - buf.data());
+}
+
+std::string MQTTComponent::get_default_topic_for_(const std::string &suffix) const {
+  char buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  StringRef ref = this->get_default_topic_for_to_(buf, suffix.data(), suffix.size());
+  return std::string(ref.c_str(), ref.size());
+}
+
+StringRef MQTTComponent::get_state_topic_to_(std::span<char, MQTT_DEFAULT_TOPIC_MAX_LEN> buf) const {
+  if (this->custom_state_topic_.has_value()) {
+    // Returns ref to existing data for static/value, uses buf only for lambda case
+    return this->custom_state_topic_.ref_or_copy_to(buf.data(), buf.size());
+  }
+  return this->get_default_topic_for_to_(buf, "state", 5);
+}
+
+StringRef MQTTComponent::get_command_topic_to_(std::span<char, MQTT_DEFAULT_TOPIC_MAX_LEN> buf) const {
+  if (this->custom_command_topic_.has_value()) {
+    // Returns ref to existing data for static/value, uses buf only for lambda case
+    return this->custom_command_topic_.ref_or_copy_to(buf.data(), buf.size());
+  }
+  return this->get_default_topic_for_to_(buf, "command", 7);
 }
 
 std::string MQTTComponent::get_state_topic_() const {
-  if (this->custom_state_topic_.has_value())
-    return this->custom_state_topic_.value();
-  return this->get_default_topic_for_("state");
+  char buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  StringRef ref = this->get_state_topic_to_(buf);
+  return std::string(ref.c_str(), ref.size());
 }
 
 std::string MQTTComponent::get_command_topic_() const {
-  if (this->custom_command_topic_.has_value())
-    return this->custom_command_topic_.value();
-  return this->get_default_topic_for_("command");
+  char buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  StringRef ref = this->get_command_topic_to_(buf);
+  return std::string(ref.c_str(), ref.size());
 }
 
 bool MQTTComponent::publish(const std::string &topic, const std::string &payload) {
@@ -167,10 +193,14 @@ bool MQTTComponent::send_discovery_() {
             break;
         }
 
-        if (config.state_topic)
-          root[MQTT_STATE_TOPIC] = this->get_state_topic_();
-        if (config.command_topic)
-          root[MQTT_COMMAND_TOPIC] = this->get_command_topic_();
+        if (config.state_topic) {
+          char state_topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+          root[MQTT_STATE_TOPIC] = this->get_state_topic_to_(state_topic_buf);
+        }
+        if (config.command_topic) {
+          char command_topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+          root[MQTT_COMMAND_TOPIC] = this->get_command_topic_to_(command_topic_buf);
+        }
         if (this->command_retain_)
           root[MQTT_COMMAND_RETAIN] = true;
 
@@ -189,27 +219,37 @@ bool MQTTComponent::send_discovery_() {
         StringRef object_id = this->get_default_object_id_to_(object_id_buf);
         if (discovery_info.unique_id_generator == MQTT_MAC_ADDRESS_UNIQUE_ID_GENERATOR) {
           char friendly_name_hash[9];
-          snprintf(friendly_name_hash, sizeof(friendly_name_hash), "%08" PRIx32, fnv1_hash(this->friendly_name_()));
+          buf_append_printf(friendly_name_hash, sizeof(friendly_name_hash), 0, "%08" PRIx32,
+                            fnv1_hash(this->friendly_name_()));
           // Format: mac-component_type-hash (e.g. "aabbccddeeff-sensor-12345678")
           // MAC (12) + "-" (1) + domain (max 20) + "-" (1) + hash (8) + null (1) = 43
           char unique_id[MAC_ADDRESS_BUFFER_SIZE + ESPHOME_DOMAIN_MAX_LEN + 11];
           char mac_buf[MAC_ADDRESS_BUFFER_SIZE];
           get_mac_address_into_buffer(mac_buf);
-          snprintf(unique_id, sizeof(unique_id), "%s-%s-%s", mac_buf, this->component_type(), friendly_name_hash);
+          buf_append_printf(unique_id, sizeof(unique_id), 0, "%s-%s-%s", mac_buf, this->component_type(),
+                            friendly_name_hash);
           root[MQTT_UNIQUE_ID] = unique_id;
         } else {
           // default to almost-unique ID. It's a hack but the only way to get that
           // gorgeous device registry view.
-          root[MQTT_UNIQUE_ID] = "ESP" + std::string(this->component_type()) + object_id.c_str();
+          // "ESP" (3) + component_type (max 20) + object_id (max 128) + null
+          char unique_id_buf[3 + MQTT_COMPONENT_TYPE_MAX_LEN + OBJECT_ID_MAX_LEN + 1];
+          buf_append_printf(unique_id_buf, sizeof(unique_id_buf), 0, "ESP%s%s", this->component_type(),
+                            object_id.c_str());
+          root[MQTT_UNIQUE_ID] = unique_id_buf;
         }
 
         const std::string &node_name = App.get_name();
-        if (discovery_info.object_id_generator == MQTT_DEVICE_NAME_OBJECT_ID_GENERATOR)
-          root[MQTT_OBJECT_ID] = node_name + "_" + object_id.c_str();
+        if (discovery_info.object_id_generator == MQTT_DEVICE_NAME_OBJECT_ID_GENERATOR) {
+          // node_name (max 31) + "_" (1) + object_id (max 128) + null
+          char object_id_full[ESPHOME_DEVICE_NAME_MAX_LEN + 1 + OBJECT_ID_MAX_LEN + 1];
+          buf_append_printf(object_id_full, sizeof(object_id_full), 0, "%s_%s", node_name.c_str(), object_id.c_str());
+          root[MQTT_OBJECT_ID] = object_id_full;
+        }
 
         const std::string &friendly_name_ref = App.get_friendly_name();
         const std::string &node_friendly_name = friendly_name_ref.empty() ? node_name : friendly_name_ref;
-        std::string node_area = App.get_area();
+        const char *node_area = App.get_area();
 
         JsonObject device_info = root[MQTT_DEVICE].to<JsonObject>();
         char mac[MAC_ADDRESS_BUFFER_SIZE];
@@ -220,18 +260,29 @@ bool MQTTComponent::send_discovery_() {
         device_info[MQTT_DEVICE_SW_VERSION] = ESPHOME_PROJECT_VERSION " (ESPHome " ESPHOME_VERSION ")";
         const char *model = std::strchr(ESPHOME_PROJECT_NAME, '.');
         device_info[MQTT_DEVICE_MODEL] = model == nullptr ? ESPHOME_BOARD : model + 1;
-        device_info[MQTT_DEVICE_MANUFACTURER] =
-            model == nullptr ? ESPHOME_PROJECT_NAME : std::string(ESPHOME_PROJECT_NAME, model - ESPHOME_PROJECT_NAME);
+        if (model == nullptr) {
+          device_info[MQTT_DEVICE_MANUFACTURER] = ESPHOME_PROJECT_NAME;
+        } else {
+          // Extract manufacturer (part before '.') using stack buffer to avoid heap allocation
+          // memcpy is used instead of strncpy since we know the exact length and strncpy
+          // would still require manual null-termination
+          char manufacturer[sizeof(ESPHOME_PROJECT_NAME)];
+          size_t len = model - ESPHOME_PROJECT_NAME;
+          memcpy(manufacturer, ESPHOME_PROJECT_NAME, len);
+          manufacturer[len] = '\0';
+          device_info[MQTT_DEVICE_MANUFACTURER] = manufacturer;
+        }
 #else
         static const char ver_fmt[] PROGMEM = ESPHOME_VERSION " (config hash 0x%08" PRIx32 ")";
+        // Buffer sized for format string expansion: ~4 bytes net growth from format specifier to 8 hex digits, plus
+        // safety margin
+        char version_buf[sizeof(ver_fmt) + 8];
 #ifdef USE_ESP8266
-        char fmt_buf[sizeof(ver_fmt)];
-        strcpy_P(fmt_buf, ver_fmt);
-        const char *fmt = fmt_buf;
+        snprintf_P(version_buf, sizeof(version_buf), ver_fmt, App.get_config_hash());
 #else
-        const char *fmt = ver_fmt;
+        snprintf(version_buf, sizeof(version_buf), ver_fmt, App.get_config_hash());
 #endif
-        device_info[MQTT_DEVICE_SW_VERSION] = str_sprintf(fmt, App.get_config_hash());
+        device_info[MQTT_DEVICE_SW_VERSION] = version_buf;
         device_info[MQTT_DEVICE_MODEL] = ESPHOME_BOARD;
 #if defined(USE_ESP8266) || defined(USE_ESP32)
         device_info[MQTT_DEVICE_MANUFACTURER] = "Espressif";
@@ -245,7 +296,7 @@ bool MQTTComponent::send_discovery_() {
         device_info[MQTT_DEVICE_MANUFACTURER] = "Host";
 #endif
 #endif
-        if (!node_area.empty()) {
+        if (node_area[0] != '\0') {
           device_info[MQTT_DEVICE_SUGGESTED_AREA] = node_area;
         }
 
@@ -287,7 +338,9 @@ void MQTTComponent::set_availability(std::string topic, std::string payload_avai
 }
 void MQTTComponent::disable_availability() { this->set_availability("", "", ""); }
 void MQTTComponent::call_setup() {
-  if (this->is_internal())
+  // Cache is_internal result once during setup - topics don't change after this
+  this->is_internal_ = this->compute_is_internal_();
+  if (this->is_internal_)
     return;
 
   this->setup();
@@ -307,16 +360,12 @@ void MQTTComponent::call_setup() {
   }
 }
 
-void MQTTComponent::call_loop() {
-  if (this->is_internal())
+void MQTTComponent::process_resend() {
+  // Called by MQTTClientComponent when connected to process pending resends
+  // Note: is_internal() check not needed - internal components are never registered
+  if (!this->resend_state_)
     return;
 
-  this->loop();
-
-  if (!this->resend_state_ || !this->is_connected_()) {
-    return;
-  }
-
   this->resend_state_ = false;
   if (this->is_discovery_enabled()) {
     if (!this->send_discovery_()) {
@@ -343,26 +392,28 @@ StringRef MQTTComponent::get_default_object_id_to_(std::span<char, OBJECT_ID_MAX
 }
 StringRef MQTTComponent::get_icon_ref_() const { return this->get_entity()->get_icon_ref(); }
 bool MQTTComponent::is_disabled_by_default_() const { return this->get_entity()->is_disabled_by_default(); }
-bool MQTTComponent::is_internal() {
+bool MQTTComponent::compute_is_internal_() {
   if (this->custom_state_topic_.has_value()) {
-    // If the custom state_topic is null, return true as it is internal and should not publish
+    // If the custom state_topic is empty, return true as it is internal and should not publish
     // else, return false, as it is explicitly set to a topic, so it is not internal and should publish
-    return this->get_state_topic_().empty();
+    // Using is_empty() avoids heap allocation for non-lambda cases
+    return this->custom_state_topic_.is_empty();
   }
 
   if (this->custom_command_topic_.has_value()) {
-    // If the custom command_topic is null, return true as it is internal and should not publish
+    // If the custom command_topic is empty, return true as it is internal and should not publish
     // else, return false, as it is explicitly set to a topic, so it is not internal and should publish
-    return this->get_command_topic_().empty();
+    // Using is_empty() avoids heap allocation for non-lambda cases
+    return this->custom_command_topic_.is_empty();
   }
 
-  // No custom topics have been set
-  if (this->get_default_topic_for_("").empty()) {
-    // If the default topic prefix is null, then the component, by default, is internal and should not publish
+  // No custom topics have been set - check topic_prefix directly to avoid allocation
+  if (global_mqtt_client->get_topic_prefix().empty()) {
+    // If the default topic prefix is empty, then the component, by default, is internal and should not publish
     return true;
   }
 
-  // Use ESPHome's component internal state if topic_prefix is not null with no custom state_topic or command_topic
+  // Use ESPHome's component internal state if topic_prefix is not empty with no custom state_topic or command_topic
   return this->get_entity()->is_internal();
 }
 
diff --git a/esphome/components/mqtt/mqtt_component.h b/esphome/components/mqtt/mqtt_component.h
index 676e3ad35d..1a5e6db3af 100644
--- a/esphome/components/mqtt/mqtt_component.h
+++ b/esphome/components/mqtt/mqtt_component.h
@@ -20,17 +20,22 @@ struct SendDiscoveryConfig {
   bool command_topic{true};  ///< If the command topic should be included. Default to true.
 };
 
-// Max lengths for stack-based topic building (must match mqtt_component.cpp)
+// Max lengths for stack-based topic building.
+// These limits are enforced at Python config validation time in mqtt/__init__.py
+// using cv.Length() validators for topic_prefix and discovery_prefix.
+// This ensures the stack buffers are always large enough.
 static constexpr size_t MQTT_COMPONENT_TYPE_MAX_LEN = 20;
 static constexpr size_t MQTT_SUFFIX_MAX_LEN = 32;
+static constexpr size_t MQTT_TOPIC_PREFIX_MAX_LEN = 64;  // Validated in Python: cv.Length(max=64)
+// Stack buffer size - safe because all inputs are length-validated at config time
+// Format: prefix + "/" + type + "/" + object_id + "/" + suffix + null
+static constexpr size_t MQTT_DEFAULT_TOPIC_MAX_LEN =
+    MQTT_TOPIC_PREFIX_MAX_LEN + 1 + MQTT_COMPONENT_TYPE_MAX_LEN + 1 + OBJECT_ID_MAX_LEN + 1 + MQTT_SUFFIX_MAX_LEN + 1;
 
-#define LOG_MQTT_COMPONENT(state_topic, command_topic) \
-  if (state_topic) { \
-    ESP_LOGCONFIG(TAG, "  State Topic: '%s'", this->get_state_topic_().c_str()); \
-  } \
-  if (command_topic) { \
-    ESP_LOGCONFIG(TAG, "  Command Topic: '%s'", this->get_command_topic_().c_str()); \
-  }
+class MQTTComponent;  // Forward declaration
+void log_mqtt_component(const char *tag, MQTTComponent *obj, bool state_topic, bool command_topic);
+
+#define LOG_MQTT_COMPONENT(state_topic, command_topic) log_mqtt_component(TAG, this, state_topic, command_topic)
 
 // Macro to define component_type() with compile-time length verification
 // Usage: MQTT_COMPONENT_TYPE(MQTTSensorComponent, "sensor")
@@ -74,6 +79,8 @@ static constexpr size_t MQTT_SUFFIX_MAX_LEN = 32;
  * a clean separation.
  */
 class MQTTComponent : public Component {
+  friend void log_mqtt_component(const char *tag, MQTTComponent *obj, bool state_topic, bool command_topic);
+
  public:
   /// Constructs a MQTTComponent.
   explicit MQTTComponent();
@@ -81,8 +88,6 @@ class MQTTComponent : public Component {
   /// Override setup_ so that we can call send_discovery() when needed.
   void call_setup() override;
 
-  void call_loop() override;
-
   void call_dump_config() override;
 
   /// Send discovery info the Home Assistant, override this.
@@ -90,7 +95,8 @@ class MQTTComponent : public Component {
 
   virtual bool send_initial_state() = 0;
 
-  virtual bool is_internal();
+  /// Returns cached is_internal result (computed once during setup).
+  bool is_internal() const { return this->is_internal_; }
 
   /// Set QOS for state messages.
   void set_qos(uint8_t qos);
@@ -133,6 +139,9 @@ class MQTTComponent : public Component {
   /// Internal method for the MQTT client base to schedule a resend of the state on reconnect.
   void schedule_resend_state();
 
+  /// Process pending resend if needed (called by MQTTClientComponent)
+  void process_resend();
+
   /** Send a MQTT message.
    *
    * @param topic The topic.
@@ -178,7 +187,16 @@ class MQTTComponent : public Component {
   /// Helper method to get the discovery topic for this component.
   std::string get_discovery_topic_(const MQTTDiscoveryInfo &discovery_info) const;
 
-  /** Get this components state/command/... topic.
+  /** Get this components state/command/... topic into a buffer.
+   *
+   * @param buf The buffer to write to (must be exactly MQTT_DEFAULT_TOPIC_MAX_LEN).
+   * @param suffix The suffix/key such as "state" or "command".
+   * @return StringRef pointing to the buffer with the topic.
+   */
+  StringRef get_default_topic_for_to_(std::span<char, MQTT_DEFAULT_TOPIC_MAX_LEN> buf, const char *suffix,
+                                      size_t suffix_len) const;
+
+  /** Get this components state/command/... topic (allocates std::string).
    *
    * @param suffix The suffix/key such as "state" or "command".
    * @return The full topic.
@@ -199,10 +217,20 @@ class MQTTComponent : public Component {
   /// Get whether the underlying Entity is disabled by default
   bool is_disabled_by_default_() const;
 
-  /// Get the MQTT topic that new states will be shared to.
+  /// Get the MQTT state topic into a buffer (no heap allocation for non-lambda custom topics).
+  /// @param buf Buffer of exactly MQTT_DEFAULT_TOPIC_MAX_LEN bytes.
+  /// @return StringRef pointing to the topic in the buffer.
+  StringRef get_state_topic_to_(std::span<char, MQTT_DEFAULT_TOPIC_MAX_LEN> buf) const;
+
+  /// Get the MQTT command topic into a buffer (no heap allocation for non-lambda custom topics).
+  /// @param buf Buffer of exactly MQTT_DEFAULT_TOPIC_MAX_LEN bytes.
+  /// @return StringRef pointing to the topic in the buffer.
+  StringRef get_command_topic_to_(std::span<char, MQTT_DEFAULT_TOPIC_MAX_LEN> buf) const;
+
+  /// Get the MQTT topic that new states will be shared to (allocates std::string).
   std::string get_state_topic_() const;
 
-  /// Get the MQTT topic for listening to commands.
+  /// Get the MQTT topic for listening to commands (allocates std::string).
   std::string get_command_topic_() const;
 
   bool is_connected_() const;
@@ -220,12 +248,18 @@ class MQTTComponent : public Component {
 
   std::unique_ptr<Availability> availability_;
 
-  bool command_retain_{false};
-  bool retain_{true};
-  uint8_t qos_{0};
-  uint8_t subscribe_qos_{0};
-  bool discovery_enabled_{true};
-  bool resend_state_{false};
+  // Packed bitfields - QoS values are 0-2, bools are flags
+  uint8_t qos_ : 2 {0};
+  uint8_t subscribe_qos_ : 2 {0};
+  bool command_retain_ : 1 {false};
+  bool retain_ : 1 {true};
+  bool discovery_enabled_ : 1 {true};
+  bool resend_state_ : 1 {false};
+  bool is_internal_ : 1 {false};  ///< Cached result of compute_is_internal_(), set during setup
+
+  /// Compute is_internal status based on topics and entity state.
+  /// Called once during setup to cache the result.
+  bool compute_is_internal_();
 };
 
 }  // namespace esphome::mqtt
diff --git a/esphome/components/mqtt/mqtt_cover.cpp b/esphome/components/mqtt/mqtt_cover.cpp
index f2df6af236..493514c8fb 100644
--- a/esphome/components/mqtt/mqtt_cover.cpp
+++ b/esphome/components/mqtt/mqtt_cover.cpp
@@ -51,7 +51,7 @@ void MQTTCoverComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT cover '%s':", this->cover_->get_name().c_str());
   auto traits = this->cover_->get_traits();
   bool has_command_topic = traits.get_supports_position() || !traits.get_supports_tilt();
-  LOG_MQTT_COMPONENT(true, has_command_topic)
+  LOG_MQTT_COMPONENT(true, has_command_topic);
   if (traits.get_supports_position()) {
     ESP_LOGCONFIG(TAG,
                   "  Position State Topic: '%s'\n"
diff --git a/esphome/components/mqtt/mqtt_date.cpp b/esphome/components/mqtt/mqtt_date.cpp
index dba7c1a671..cbe4045486 100644
--- a/esphome/components/mqtt/mqtt_date.cpp
+++ b/esphome/components/mqtt/mqtt_date.cpp
@@ -36,7 +36,7 @@ void MQTTDateComponent::setup() {
 
 void MQTTDateComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT Date '%s':", this->date_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, true)
+  LOG_MQTT_COMPONENT(true, true);
 }
 
 MQTT_COMPONENT_TYPE(MQTTDateComponent, "date")
diff --git a/esphome/components/mqtt/mqtt_datetime.cpp b/esphome/components/mqtt/mqtt_datetime.cpp
index 5f1cf19b97..f7b4ef0685 100644
--- a/esphome/components/mqtt/mqtt_datetime.cpp
+++ b/esphome/components/mqtt/mqtt_datetime.cpp
@@ -47,7 +47,7 @@ void MQTTDateTimeComponent::setup() {
 
 void MQTTDateTimeComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT DateTime '%s':", this->datetime_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, true)
+  LOG_MQTT_COMPONENT(true, true);
 }
 
 MQTT_COMPONENT_TYPE(MQTTDateTimeComponent, "datetime")
diff --git a/esphome/components/mqtt/mqtt_fan.cpp b/esphome/components/mqtt/mqtt_fan.cpp
index a6f0503588..0909090023 100644
--- a/esphome/components/mqtt/mqtt_fan.cpp
+++ b/esphome/components/mqtt/mqtt_fan.cpp
@@ -175,7 +175,7 @@ bool MQTTFanComponent::publish_state() {
   auto traits = this->state_->get_traits();
   if (traits.supports_speed()) {
     char buf[12];
-    int len = snprintf(buf, sizeof(buf), "%d", this->state_->speed);
+    size_t len = buf_append_printf(buf, sizeof(buf), 0, "%d", this->state_->speed);
     bool success = this->publish(this->get_speed_level_state_topic(), buf, len);
     failed = failed || !success;
   }
diff --git a/esphome/components/mqtt/mqtt_light.cpp b/esphome/components/mqtt/mqtt_light.cpp
index fac19f3210..e43cb63f4f 100644
--- a/esphome/components/mqtt/mqtt_light.cpp
+++ b/esphome/components/mqtt/mqtt_light.cpp
@@ -90,7 +90,7 @@ void MQTTJSONLightComponent::send_discovery(JsonObject root, mqtt::SendDiscovery
 bool MQTTJSONLightComponent::send_initial_state() { return this->publish_state_(); }
 void MQTTJSONLightComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT Light '%s':", this->state_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, true)
+  LOG_MQTT_COMPONENT(true, true);
 }
 
 }  // namespace esphome::mqtt
diff --git a/esphome/components/mqtt/mqtt_number.cpp b/esphome/components/mqtt/mqtt_number.cpp
index 8342210ee4..a014096c5f 100644
--- a/esphome/components/mqtt/mqtt_number.cpp
+++ b/esphome/components/mqtt/mqtt_number.cpp
@@ -30,7 +30,7 @@ void MQTTNumberComponent::setup() {
 
 void MQTTNumberComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT Number '%s':", this->number_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, false)
+  LOG_MQTT_COMPONENT(true, false);
 }
 
 MQTT_COMPONENT_TYPE(MQTTNumberComponent, "number")
@@ -75,7 +75,7 @@ bool MQTTNumberComponent::send_initial_state() {
 }
 bool MQTTNumberComponent::publish_state(float value) {
   char buffer[64];
-  snprintf(buffer, sizeof(buffer), "%f", value);
+  buf_append_printf(buffer, sizeof(buffer), 0, "%f", value);
   return this->publish(this->get_state_topic_(), buffer);
 }
 
diff --git a/esphome/components/mqtt/mqtt_select.cpp b/esphome/components/mqtt/mqtt_select.cpp
index 03ab82312b..2d830998ec 100644
--- a/esphome/components/mqtt/mqtt_select.cpp
+++ b/esphome/components/mqtt/mqtt_select.cpp
@@ -25,7 +25,7 @@ void MQTTSelectComponent::setup() {
 
 void MQTTSelectComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT Select '%s':", this->select_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, false)
+  LOG_MQTT_COMPONENT(true, false);
 }
 
 MQTT_COMPONENT_TYPE(MQTTSelectComponent, "select")
diff --git a/esphome/components/mqtt/mqtt_sensor.cpp b/esphome/components/mqtt/mqtt_sensor.cpp
index c14c889d47..f136b82355 100644
--- a/esphome/components/mqtt/mqtt_sensor.cpp
+++ b/esphome/components/mqtt/mqtt_sensor.cpp
@@ -28,7 +28,7 @@ void MQTTSensorComponent::dump_config() {
   if (this->get_expire_after() > 0) {
     ESP_LOGCONFIG(TAG, "  Expire After: %" PRIu32 "s", this->get_expire_after() / 1000);
   }
-  LOG_MQTT_COMPONENT(true, false)
+  LOG_MQTT_COMPONENT(true, false);
 }
 
 MQTT_COMPONENT_TYPE(MQTTSensorComponent, "sensor")
diff --git a/esphome/components/mqtt/mqtt_text.cpp b/esphome/components/mqtt/mqtt_text.cpp
index cee94965c6..fed9224b42 100644
--- a/esphome/components/mqtt/mqtt_text.cpp
+++ b/esphome/components/mqtt/mqtt_text.cpp
@@ -26,7 +26,7 @@ void MQTTTextComponent::setup() {
 
 void MQTTTextComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT text '%s':", this->text_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, true)
+  LOG_MQTT_COMPONENT(true, true);
 }
 
 MQTT_COMPONENT_TYPE(MQTTTextComponent, "text")
diff --git a/esphome/components/mqtt/mqtt_time.cpp b/esphome/components/mqtt/mqtt_time.cpp
index b75325022a..8749c3b59e 100644
--- a/esphome/components/mqtt/mqtt_time.cpp
+++ b/esphome/components/mqtt/mqtt_time.cpp
@@ -36,7 +36,7 @@ void MQTTTimeComponent::setup() {
 
 void MQTTTimeComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT Time '%s':", this->time_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, true)
+  LOG_MQTT_COMPONENT(true, true);
 }
 
 MQTT_COMPONENT_TYPE(MQTTTimeComponent, "time")
diff --git a/esphome/components/mqtt/mqtt_valve.cpp b/esphome/components/mqtt/mqtt_valve.cpp
index 2faaace46b..8e66a69c6f 100644
--- a/esphome/components/mqtt/mqtt_valve.cpp
+++ b/esphome/components/mqtt/mqtt_valve.cpp
@@ -39,7 +39,7 @@ void MQTTValveComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT valve '%s':", this->valve_->get_name().c_str());
   auto traits = this->valve_->get_traits();
   bool has_command_topic = traits.get_supports_position();
-  LOG_MQTT_COMPONENT(true, has_command_topic)
+  LOG_MQTT_COMPONENT(true, has_command_topic);
   if (traits.get_supports_position()) {
     ESP_LOGCONFIG(TAG,
                   "  Position State Topic: '%s'\n"
diff --git a/esphome/components/network/ip_address.h b/esphome/components/network/ip_address.h
index b719d1a70e..d0ac8164af 100644
--- a/esphome/components/network/ip_address.h
+++ b/esphome/components/network/ip_address.h
@@ -43,6 +43,14 @@ namespace network {
 /// Buffer size for IP address string (IPv6 max: 39 chars + null)
 static constexpr size_t IP_ADDRESS_BUFFER_SIZE = 40;
 
+/// Lowercase hex digits in IP address string (A-F -> a-f for IPv6 per RFC 5952)
+inline void lowercase_ip_str(char *buf) {
+  for (char *p = buf; *p; ++p) {
+    if (*p >= 'A' && *p <= 'F')
+      *p += 32;
+  }
+}
+
 struct IPAddress {
  public:
 #ifdef USE_HOST
@@ -52,10 +60,17 @@ struct IPAddress {
   }
   IPAddress(const std::string &in_address) { inet_aton(in_address.c_str(), &ip_addr_); }
   IPAddress(const ip_addr_t *other_ip) { ip_addr_ = *other_ip; }
-  std::string str() const { return str_lower_case(inet_ntoa(ip_addr_)); }
+  // Remove before 2026.8.0
+  ESPDEPRECATED("Use str_to() instead. Removed in 2026.8.0", "2026.2.0")
+  std::string str() const {
+    char buf[IP_ADDRESS_BUFFER_SIZE];
+    this->str_to(buf);
+    return buf;
+  }
   /// Write IP address to buffer. Buffer must be at least IP_ADDRESS_BUFFER_SIZE bytes.
   char *str_to(char *buf) const {
-    return const_cast<char *>(inet_ntop(AF_INET, &ip_addr_, buf, IP_ADDRESS_BUFFER_SIZE));
+    inet_ntop(AF_INET, &ip_addr_, buf, IP_ADDRESS_BUFFER_SIZE);
+    return buf;  // IPv4 only, no hex letters to lowercase
   }
 #else
   IPAddress() { ip_addr_set_zero(&ip_addr_); }
@@ -134,9 +149,20 @@ struct IPAddress {
   bool is_ip4() const { return IP_IS_V4(&ip_addr_); }
   bool is_ip6() const { return IP_IS_V6(&ip_addr_); }
   bool is_multicast() const { return ip_addr_ismulticast(&ip_addr_); }
-  std::string str() const { return str_lower_case(ipaddr_ntoa(&ip_addr_)); }
+  // Remove before 2026.8.0
+  ESPDEPRECATED("Use str_to() instead. Removed in 2026.8.0", "2026.2.0")
+  std::string str() const {
+    char buf[IP_ADDRESS_BUFFER_SIZE];
+    this->str_to(buf);
+    return buf;
+  }
   /// Write IP address to buffer. Buffer must be at least IP_ADDRESS_BUFFER_SIZE bytes.
-  char *str_to(char *buf) const { return ipaddr_ntoa_r(&ip_addr_, buf, IP_ADDRESS_BUFFER_SIZE); }
+  /// Output is lowercased per RFC 5952 (IPv6 hex digits a-f).
+  char *str_to(char *buf) const {
+    ipaddr_ntoa_r(&ip_addr_, buf, IP_ADDRESS_BUFFER_SIZE);
+    lowercase_ip_str(buf);
+    return buf;
+  }
   bool operator==(const IPAddress &other) const { return ip_addr_cmp(&ip_addr_, &other.ip_addr_); }
   bool operator!=(const IPAddress &other) const { return !ip_addr_cmp(&ip_addr_, &other.ip_addr_); }
   IPAddress &operator+=(uint8_t increase) {
diff --git a/esphome/components/nextion/base_component.py b/esphome/components/nextion/base_component.py
index 392481e39a..86551cbe23 100644
--- a/esphome/components/nextion/base_component.py
+++ b/esphome/components/nextion/base_component.py
@@ -16,6 +16,7 @@ CONF_EXIT_REPARSE_ON_START = "exit_reparse_on_start"
 CONF_FONT_ID = "font_id"
 CONF_FOREGROUND_PRESSED_COLOR = "foreground_pressed_color"
 CONF_MAX_COMMANDS_PER_LOOP = "max_commands_per_loop"
+CONF_MAX_QUEUE_AGE = "max_queue_age"
 CONF_MAX_QUEUE_SIZE = "max_queue_size"
 CONF_ON_BUFFER_OVERFLOW = "on_buffer_overflow"
 CONF_ON_PAGE = "on_page"
@@ -25,6 +26,7 @@ CONF_ON_WAKE = "on_wake"
 CONF_PRECISION = "precision"
 CONF_SKIP_CONNECTION_HANDSHAKE = "skip_connection_handshake"
 CONF_START_UP_PAGE = "start_up_page"
+CONF_STARTUP_OVERRIDE_MS = "startup_override_ms"
 CONF_TFT_URL = "tft_url"
 CONF_TOUCH_SLEEP_TIMEOUT = "touch_sleep_timeout"
 CONF_VARIABLE_NAME = "variable_name"
diff --git a/esphome/components/nextion/display.py b/esphome/components/nextion/display.py
index 0b4ba3a171..ffc509fc64 100644
--- a/esphome/components/nextion/display.py
+++ b/esphome/components/nextion/display.py
@@ -23,6 +23,7 @@ from .base_component import (
     CONF_DUMP_DEVICE_INFO,
     CONF_EXIT_REPARSE_ON_START,
     CONF_MAX_COMMANDS_PER_LOOP,
+    CONF_MAX_QUEUE_AGE,
     CONF_MAX_QUEUE_SIZE,
     CONF_ON_BUFFER_OVERFLOW,
     CONF_ON_PAGE,
@@ -31,6 +32,7 @@ from .base_component import (
     CONF_ON_WAKE,
     CONF_SKIP_CONNECTION_HANDSHAKE,
     CONF_START_UP_PAGE,
+    CONF_STARTUP_OVERRIDE_MS,
     CONF_TFT_URL,
     CONF_TOUCH_SLEEP_TIMEOUT,
     CONF_WAKE_UP_PAGE,
@@ -65,6 +67,12 @@ CONFIG_SCHEMA = (
             ),
             cv.Optional(CONF_DUMP_DEVICE_INFO, default=False): cv.boolean,
             cv.Optional(CONF_EXIT_REPARSE_ON_START, default=False): cv.boolean,
+            cv.Optional(CONF_MAX_QUEUE_AGE, default="8000ms"): cv.All(
+                cv.positive_time_period_milliseconds,
+                cv.Range(
+                    min=TimePeriod(milliseconds=0), max=TimePeriod(milliseconds=65535)
+                ),
+            ),
             cv.Optional(CONF_MAX_COMMANDS_PER_LOOP): cv.uint16_t,
             cv.Optional(CONF_MAX_QUEUE_SIZE): cv.positive_int,
             cv.Optional(CONF_ON_BUFFER_OVERFLOW): automation.validate_automation(
@@ -100,6 +108,12 @@ CONFIG_SCHEMA = (
                 }
             ),
             cv.Optional(CONF_SKIP_CONNECTION_HANDSHAKE, default=False): cv.boolean,
+            cv.Optional(CONF_STARTUP_OVERRIDE_MS, default="8000ms"): cv.All(
+                cv.positive_time_period_milliseconds,
+                cv.Range(
+                    min=TimePeriod(milliseconds=0), max=TimePeriod(milliseconds=65535)
+                ),
+            ),
             cv.Optional(CONF_START_UP_PAGE): cv.uint8_t,
             cv.Optional(CONF_TFT_URL): cv.url,
             cv.Optional(CONF_TOUCH_SLEEP_TIMEOUT): cv.Any(
@@ -138,6 +152,8 @@ async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await uart.register_uart_device(var, config)
 
+    cg.add(var.set_max_queue_age(config[CONF_MAX_QUEUE_AGE]))
+
     if max_queue_size := config.get(CONF_MAX_QUEUE_SIZE):
         cg.add_define("USE_NEXTION_MAX_QUEUE_SIZE")
         cg.add(var.set_max_queue_size(max_queue_size))
@@ -146,6 +162,8 @@ async def to_code(config):
         cg.add_define("USE_NEXTION_COMMAND_SPACING")
         cg.add(var.set_command_spacing(command_spacing.total_milliseconds))
 
+    cg.add(var.set_startup_override_ms(config[CONF_STARTUP_OVERRIDE_MS]))
+
     if CONF_BRIGHTNESS in config:
         cg.add(var.set_brightness(config[CONF_BRIGHTNESS]))
 
diff --git a/esphome/components/nextion/nextion.cpp b/esphome/components/nextion/nextion.cpp
index d77af510d7..4bba33f961 100644
--- a/esphome/components/nextion/nextion.cpp
+++ b/esphome/components/nextion/nextion.cpp
@@ -1,6 +1,7 @@
 #include "nextion.h"
 #include <cinttypes>
 #include "esphome/core/application.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 #include "esphome/core/util.h"
 
@@ -151,21 +152,25 @@ void Nextion::dump_config() {
 #else  // USE_NEXTION_CONFIG_SKIP_CONNECTION_HANDSHAKE
   ESP_LOGCONFIG(TAG,
 #ifdef USE_NEXTION_CONFIG_DUMP_DEVICE_INFO
-                "  Device Model:   %s\n"
-                "  FW Version:     %s\n"
-                "  Serial Number:  %s\n"
-                "  Flash Size:     %s\n"
+                "  Device Model: %s\n"
+                "  FW Version: %s\n"
+                "  Serial Number: %s\n"
+                "  Flash Size: %s\n"
+                "  Max queue age: %u ms\n"
+                "  Startup override: %u ms\n",
 #endif  // USE_NEXTION_CONFIG_DUMP_DEVICE_INFO
 #ifdef USE_NEXTION_CONFIG_EXIT_REPARSE_ON_START
-                "  Exit reparse:   YES\n"
+                "  Exit reparse: YES\n"
 #endif  // USE_NEXTION_CONFIG_EXIT_REPARSE_ON_START
-                "  Wake On Touch:  %s\n"
-                "  Touch Timeout:  %" PRIu16,
+                "  Wake On Touch: %s\n"
+                "  Touch Timeout: %" PRIu16,
 #ifdef USE_NEXTION_CONFIG_DUMP_DEVICE_INFO
                 this->device_model_.c_str(), this->firmware_version_.c_str(), this->serial_number_.c_str(),
-                this->flash_size_.c_str(),
+                this->flash_size_.c_str(), this->max_q_age_ms_,
+                this->startup_override_ms_
 #endif  // USE_NEXTION_CONFIG_DUMP_DEVICE_INFO
-                YESNO(this->connection_state_.auto_wake_on_touch_), this->touch_sleep_timeout_);
+                    YESNO(this->connection_state_.auto_wake_on_touch_),
+                this->touch_sleep_timeout_);
 #endif  // USE_NEXTION_CONFIG_SKIP_CONNECTION_HANDSHAKE
 
 #ifdef USE_NEXTION_MAX_COMMANDS_PER_LOOP
@@ -173,21 +178,21 @@ void Nextion::dump_config() {
 #endif  // USE_NEXTION_MAX_COMMANDS_PER_LOOP
 
   if (this->wake_up_page_ != 255) {
-    ESP_LOGCONFIG(TAG, "  Wake Up Page:   %u", this->wake_up_page_);
+    ESP_LOGCONFIG(TAG, "  Wake Up Page: %u", this->wake_up_page_);
   }
 
 #ifdef USE_NEXTION_CONF_START_UP_PAGE
   if (this->start_up_page_ != 255) {
-    ESP_LOGCONFIG(TAG, "  Start Up Page:  %u", this->start_up_page_);
+    ESP_LOGCONFIG(TAG, "  Start Up Page: %u", this->start_up_page_);
   }
 #endif  // USE_NEXTION_CONF_START_UP_PAGE
 
 #ifdef USE_NEXTION_COMMAND_SPACING
-  ESP_LOGCONFIG(TAG, "  Cmd spacing:      %u ms", this->command_pacer_.get_spacing());
+  ESP_LOGCONFIG(TAG, "  Cmd spacing: %u ms", this->command_pacer_.get_spacing());
 #endif  // USE_NEXTION_COMMAND_SPACING
 
 #ifdef USE_NEXTION_MAX_QUEUE_SIZE
-  ESP_LOGCONFIG(TAG, "  Max queue size:   %zu", this->max_queue_size_);
+  ESP_LOGCONFIG(TAG, "  Max queue size: %zu", this->max_queue_size_);
 #endif
 }
 
@@ -335,7 +340,8 @@ void Nextion::loop() {
     if (this->started_ms_ == 0)
       this->started_ms_ = App.get_loop_component_start_time();
 
-    if (this->started_ms_ + this->startup_override_ms_ < App.get_loop_component_start_time()) {
+    if (this->startup_override_ms_ > 0 &&
+        this->started_ms_ + this->startup_override_ms_ < App.get_loop_component_start_time()) {
       ESP_LOGV(TAG, "Manual ready set");
       this->connection_state_.nextion_reports_is_setup_ = true;
     }
@@ -844,7 +850,8 @@ void Nextion::process_nextion_commands_() {
 
   const uint32_t ms = App.get_loop_component_start_time();
 
-  if (!this->nextion_queue_.empty() && this->nextion_queue_.front()->queue_time + this->max_q_age_ms_ < ms) {
+  if (this->max_q_age_ms_ > 0 && !this->nextion_queue_.empty() &&
+      this->nextion_queue_.front()->queue_time + this->max_q_age_ms_ < ms) {
     for (size_t i = 0; i < this->nextion_queue_.size(); i++) {
       NextionComponentBase *component = this->nextion_queue_[i]->component;
       if (this->nextion_queue_[i]->queue_time + this->max_q_age_ms_ < ms) {
@@ -1283,8 +1290,9 @@ void Nextion::check_pending_waveform_() {
   size_t buffer_to_send = component->get_wave_buffer_size() < 255 ? component->get_wave_buffer_size()
                                                                   : 255;  // ADDT command can only send 255
 
-  std::string command = "addt " + to_string(component->get_component_id()) + "," +
-                        to_string(component->get_wave_channel_id()) + "," + to_string(buffer_to_send);
+  char command[24];  // "addt " + uint8 + "," + uint8 + "," + uint8 + null = max 17 chars
+  buf_append_printf(command, sizeof(command), 0, "addt %u,%u,%zu", component->get_component_id(),
+                    component->get_wave_channel_id(), buffer_to_send);
   if (!this->send_command_(command)) {
     delete nb;  // NOLINT(cppcoreguidelines-owning-memory)
     this->waveform_queue_.pop_front();
diff --git a/esphome/components/nextion/nextion.h b/esphome/components/nextion/nextion.h
index 331e901578..c543e14bfe 100644
--- a/esphome/components/nextion/nextion.h
+++ b/esphome/components/nextion/nextion.h
@@ -1309,6 +1309,30 @@ class Nextion : public NextionBase, public PollingComponent, public uart::UARTDe
    */
   bool is_connected() { return this->connection_state_.is_connected_; }
 
+  /**
+   * @brief Set the maximum age for queue items
+   * @param age_ms Maximum age in milliseconds before queue items are removed
+   */
+  inline void set_max_queue_age(uint16_t age_ms) { this->max_q_age_ms_ = age_ms; }
+
+  /**
+   * @brief Get the maximum age for queue items
+   * @return Maximum age in milliseconds
+   */
+  inline uint16_t get_max_queue_age() const { return this->max_q_age_ms_; }
+
+  /**
+   * @brief Set the startup override timeout
+   * @param timeout_ms Time in milliseconds to wait before forcing setup complete
+   */
+  inline void set_startup_override_ms(uint16_t timeout_ms) { this->startup_override_ms_ = timeout_ms; }
+
+  /**
+   * @brief Get the startup override timeout
+   * @return Startup override timeout in milliseconds
+   */
+  inline uint16_t get_startup_override_ms() const { return this->startup_override_ms_; }
+
  protected:
 #ifdef USE_NEXTION_MAX_COMMANDS_PER_LOOP
   uint16_t max_commands_per_loop_{1000};
@@ -1479,9 +1503,10 @@ class Nextion : public NextionBase, public PollingComponent, public uart::UARTDe
   void reset_(bool reset_nextion = true);
 
   std::string command_data_;
-  const uint16_t startup_override_ms_ = 8000;
-  const uint16_t max_q_age_ms_ = 8000;
   uint32_t started_ms_ = 0;
+
+  uint16_t startup_override_ms_ = 8000;  ///< Timeout before forcing setup complete
+  uint16_t max_q_age_ms_ = 8000;         ///< Maximum age for queue items in ms
 };
 
 }  // namespace nextion
diff --git a/esphome/components/nextion/nextion_upload_arduino.cpp b/esphome/components/nextion/nextion_upload_arduino.cpp
index d210bad004..220c75f9d3 100644
--- a/esphome/components/nextion/nextion_upload_arduino.cpp
+++ b/esphome/components/nextion/nextion_upload_arduino.cpp
@@ -34,7 +34,7 @@ int Nextion::upload_by_chunks_(HTTPClient &http_client, uint32_t &range_start) {
   }
 
   char range_header[32];
-  sprintf(range_header, "bytes=%" PRIu32 "-%" PRIu32, range_start, range_end);
+  buf_append_printf(range_header, sizeof(range_header), 0, "bytes=%" PRIu32 "-%" PRIu32, range_start, range_end);
   ESP_LOGV(TAG, "Range: %s", range_header);
   http_client.addHeader("Range", range_header);
   int code = http_client.GET();
diff --git a/esphome/components/nextion/nextion_upload_esp32.cpp b/esphome/components/nextion/nextion_upload_esp32.cpp
index 712fa8e78e..c4e6ff7182 100644
--- a/esphome/components/nextion/nextion_upload_esp32.cpp
+++ b/esphome/components/nextion/nextion_upload_esp32.cpp
@@ -36,7 +36,7 @@ int Nextion::upload_by_chunks_(esp_http_client_handle_t http_client, uint32_t &r
   }
 
   char range_header[32];
-  sprintf(range_header, "bytes=%" PRIu32 "-%" PRIu32, range_start, range_end);
+  buf_append_printf(range_header, sizeof(range_header), 0, "bytes=%" PRIu32 "-%" PRIu32, range_start, range_end);
   ESP_LOGV(TAG, "Range: %s", range_header);
   esp_http_client_set_header(http_client, "Range", range_header);
   ESP_LOGV(TAG, "Open HTTP");
diff --git a/esphome/components/opentherm/opentherm.cpp b/esphome/components/opentherm/opentherm.cpp
index c6443f1282..2bf438a52f 100644
--- a/esphome/components/opentherm/opentherm.cpp
+++ b/esphome/components/opentherm/opentherm.cpp
@@ -561,8 +561,9 @@ const char *OpenTherm::message_id_to_str(MessageId id) {
 }
 
 void OpenTherm::debug_data(OpenthermData &data) {
-  ESP_LOGD(TAG, "%s %s %s %s", format_bin(data.type).c_str(), format_bin(data.id).c_str(),
-           format_bin(data.valueHB).c_str(), format_bin(data.valueLB).c_str());
+  char type_buf[9], id_buf[9], hb_buf[9], lb_buf[9];
+  ESP_LOGD(TAG, "%s %s %s %s", format_bin_to(type_buf, data.type), format_bin_to(id_buf, data.id),
+           format_bin_to(hb_buf, data.valueHB), format_bin_to(lb_buf, data.valueLB));
   ESP_LOGD(TAG, "type: %s; id: %u; HB: %u; LB: %u; uint_16: %u; float: %f",
            this->message_type_to_str((MessageType) data.type), data.id, data.valueHB, data.valueLB, data.u16(),
            data.f88());
diff --git a/esphome/components/pca6416a/pca6416a.cpp b/esphome/components/pca6416a/pca6416a.cpp
index 909bac5f05..f393af88ce 100644
--- a/esphome/components/pca6416a/pca6416a.cpp
+++ b/esphome/components/pca6416a/pca6416a.cpp
@@ -181,7 +181,7 @@ void PCA6416AGPIOPin::pin_mode(gpio::Flags flags) { this->parent_->pin_mode(this
 bool PCA6416AGPIOPin::digital_read() { return this->parent_->digital_read(this->pin_) != this->inverted_; }
 void PCA6416AGPIOPin::digital_write(bool value) { this->parent_->digital_write(this->pin_, value != this->inverted_); }
 size_t PCA6416AGPIOPin::dump_summary(char *buffer, size_t len) const {
-  return snprintf(buffer, len, "%u via PCA6416A", this->pin_);
+  return buf_append_printf(buffer, len, 0, "%u via PCA6416A", this->pin_);
 }
 
 }  // namespace pca6416a
diff --git a/esphome/components/pca9554/pca9554.cpp b/esphome/components/pca9554/pca9554.cpp
index a6f9c2396c..c574ce6593 100644
--- a/esphome/components/pca9554/pca9554.cpp
+++ b/esphome/components/pca9554/pca9554.cpp
@@ -130,7 +130,7 @@ void PCA9554GPIOPin::pin_mode(gpio::Flags flags) { this->parent_->pin_mode(this-
 bool PCA9554GPIOPin::digital_read() { return this->parent_->digital_read(this->pin_) != this->inverted_; }
 void PCA9554GPIOPin::digital_write(bool value) { this->parent_->digital_write(this->pin_, value != this->inverted_); }
 size_t PCA9554GPIOPin::dump_summary(char *buffer, size_t len) const {
-  return snprintf(buffer, len, "%u via PCA9554", this->pin_);
+  return buf_append_printf(buffer, len, 0, "%u via PCA9554", this->pin_);
 }
 
 }  // namespace pca9554
diff --git a/esphome/components/pcd8544/display.py b/esphome/components/pcd8544/display.py
index 2c24b133da..9d993c2105 100644
--- a/esphome/components/pcd8544/display.py
+++ b/esphome/components/pcd8544/display.py
@@ -44,7 +44,7 @@ async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
 
     await display.register_display(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/pcf8574/pcf8574.cpp b/esphome/components/pcf8574/pcf8574.cpp
index 8bdd312ab9..b7d3848f0e 100644
--- a/esphome/components/pcf8574/pcf8574.cpp
+++ b/esphome/components/pcf8574/pcf8574.cpp
@@ -107,7 +107,7 @@ void PCF8574GPIOPin::pin_mode(gpio::Flags flags) { this->parent_->pin_mode(this-
 bool PCF8574GPIOPin::digital_read() { return this->parent_->digital_read(this->pin_) != this->inverted_; }
 void PCF8574GPIOPin::digital_write(bool value) { this->parent_->digital_write(this->pin_, value != this->inverted_); }
 size_t PCF8574GPIOPin::dump_summary(char *buffer, size_t len) const {
-  return snprintf(buffer, len, "%u via PCF8574", this->pin_);
+  return buf_append_printf(buffer, len, 0, "%u via PCF8574", this->pin_);
 }
 
 }  // namespace pcf8574
diff --git a/esphome/components/pi4ioe5v6408/pi4ioe5v6408.cpp b/esphome/components/pi4ioe5v6408/pi4ioe5v6408.cpp
index f3a1f013d9..fdff11dedb 100644
--- a/esphome/components/pi4ioe5v6408/pi4ioe5v6408.cpp
+++ b/esphome/components/pi4ioe5v6408/pi4ioe5v6408.cpp
@@ -165,7 +165,7 @@ void PI4IOE5V6408GPIOPin::digital_write(bool value) {
   this->parent_->digital_write(this->pin_, value != this->inverted_);
 }
 size_t PI4IOE5V6408GPIOPin::dump_summary(char *buffer, size_t len) const {
-  return snprintf(buffer, len, "%u via PI4IOE5V6408", this->pin_);
+  return buf_append_printf(buffer, len, 0, "%u via PI4IOE5V6408", this->pin_);
 }
 
 }  // namespace pi4ioe5v6408
diff --git a/esphome/components/pipsolar/output/pipsolar_output.cpp b/esphome/components/pipsolar/output/pipsolar_output.cpp
index 163fbf4eb2..60f6342759 100644
--- a/esphome/components/pipsolar/output/pipsolar_output.cpp
+++ b/esphome/components/pipsolar/output/pipsolar_output.cpp
@@ -8,8 +8,8 @@ namespace pipsolar {
 static const char *const TAG = "pipsolar.output";
 
 void PipsolarOutput::write_state(float state) {
-  char tmp[10];
-  sprintf(tmp, this->set_command_.c_str(), state);
+  char tmp[16];
+  snprintf(tmp, sizeof(tmp), this->set_command_, state);
 
   if (std::find(this->possible_values_.begin(), this->possible_values_.end(), state) != this->possible_values_.end()) {
     ESP_LOGD(TAG, "Will write: %s out of value %f / %02.0f", tmp, state, state);
diff --git a/esphome/components/pipsolar/output/pipsolar_output.h b/esphome/components/pipsolar/output/pipsolar_output.h
index b4b8000962..66eda8e391 100644
--- a/esphome/components/pipsolar/output/pipsolar_output.h
+++ b/esphome/components/pipsolar/output/pipsolar_output.h
@@ -15,13 +15,15 @@ class PipsolarOutput : public output::FloatOutput {
  public:
   PipsolarOutput() {}
   void set_parent(Pipsolar *parent) { this->parent_ = parent; }
-  void set_set_command(const std::string &command) { this->set_command_ = command; };
+  void set_set_command(const char *command) { this->set_command_ = command; }
+  /// Prevent accidental use of std::string which would dangle
+  void set_set_command(const std::string &command) = delete;
   void set_possible_values(std::vector<float> possible_values) { this->possible_values_ = std::move(possible_values); }
-  void set_value(float value) { this->write_state(value); };
+  void set_value(float value) { this->write_state(value); }
 
  protected:
   void write_state(float state) override;
-  std::string set_command_;
+  const char *set_command_{nullptr};
   Pipsolar *parent_;
   std::vector<float> possible_values_;
 };
diff --git a/esphome/components/pipsolar/switch/pipsolar_switch.cpp b/esphome/components/pipsolar/switch/pipsolar_switch.cpp
index 649d951618..512587511b 100644
--- a/esphome/components/pipsolar/switch/pipsolar_switch.cpp
+++ b/esphome/components/pipsolar/switch/pipsolar_switch.cpp
@@ -9,14 +9,9 @@ static const char *const TAG = "pipsolar.switch";
 
 void PipsolarSwitch::dump_config() { LOG_SWITCH("", "Pipsolar Switch", this); }
 void PipsolarSwitch::write_state(bool state) {
-  if (state) {
-    if (!this->on_command_.empty()) {
-      this->parent_->queue_command(this->on_command_);
-    }
-  } else {
-    if (!this->off_command_.empty()) {
-      this->parent_->queue_command(this->off_command_);
-    }
+  const char *command = state ? this->on_command_ : this->off_command_;
+  if (command != nullptr) {
+    this->parent_->queue_command(command);
   }
 }
 
diff --git a/esphome/components/pipsolar/switch/pipsolar_switch.h b/esphome/components/pipsolar/switch/pipsolar_switch.h
index 11ff6c853a..bb62d4794a 100644
--- a/esphome/components/pipsolar/switch/pipsolar_switch.h
+++ b/esphome/components/pipsolar/switch/pipsolar_switch.h
@@ -9,15 +9,18 @@ namespace pipsolar {
 class Pipsolar;
 class PipsolarSwitch : public switch_::Switch, public Component {
  public:
-  void set_parent(Pipsolar *parent) { this->parent_ = parent; };
-  void set_on_command(const std::string &command) { this->on_command_ = command; };
-  void set_off_command(const std::string &command) { this->off_command_ = command; };
+  void set_parent(Pipsolar *parent) { this->parent_ = parent; }
+  void set_on_command(const char *command) { this->on_command_ = command; }
+  void set_off_command(const char *command) { this->off_command_ = command; }
+  /// Prevent accidental use of std::string which would dangle
+  void set_on_command(const std::string &command) = delete;
+  void set_off_command(const std::string &command) = delete;
   void dump_config() override;
 
  protected:
   void write_state(bool state) override;
-  std::string on_command_;
-  std::string off_command_;
+  const char *on_command_{nullptr};
+  const char *off_command_{nullptr};
   Pipsolar *parent_;
 };
 
diff --git a/esphome/components/qspi_dbi/display.py b/esphome/components/qspi_dbi/display.py
index e4440c9b81..48d1f6d12e 100644
--- a/esphome/components/qspi_dbi/display.py
+++ b/esphome/components/qspi_dbi/display.py
@@ -161,7 +161,7 @@ CONFIG_SCHEMA = cv.All(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await display.register_display(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     chip = DriverChip.chips[config[CONF_MODEL]]
     if chip.initsequence:
diff --git a/esphome/components/rc522_spi/rc522_spi.cpp b/esphome/components/rc522_spi/rc522_spi.cpp
index 23e92be65a..40da449814 100644
--- a/esphome/components/rc522_spi/rc522_spi.cpp
+++ b/esphome/components/rc522_spi/rc522_spi.cpp
@@ -1,4 +1,5 @@
 #include "rc522_spi.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
 // Based on:
@@ -70,7 +71,7 @@ void RC522Spi::pcd_read_register(PcdRegister reg,  ///< The register to read fro
     index++;
 
 #ifdef ESPHOME_LOG_HAS_VERY_VERBOSE
-    sprintf(cstrb, " %x", values[0]);
+    buf_append_printf(cstrb, sizeof(cstrb), 0, " %x", values[0]);
     buf.append(cstrb);
 #endif
   }
@@ -78,7 +79,7 @@ void RC522Spi::pcd_read_register(PcdRegister reg,  ///< The register to read fro
     values[index] = transfer_byte(address);  // Read value and tell that we want to read the same address again.
 
 #ifdef ESPHOME_LOG_HAS_VERY_VERBOSE
-    sprintf(cstrb, " %x", values[index]);
+    buf_append_printf(cstrb, sizeof(cstrb), 0, " %x", values[index]);
     buf.append(cstrb);
 #endif
 
@@ -88,7 +89,7 @@ void RC522Spi::pcd_read_register(PcdRegister reg,  ///< The register to read fro
 
 #ifdef ESPHOME_LOG_HAS_VERY_VERBOSE
   buf = buf + " ";
-  sprintf(cstrb, "%x", values[index]);
+  buf_append_printf(cstrb, sizeof(cstrb), 0, "%x", values[index]);
   buf.append(cstrb);
 
   ESP_LOGVV(TAG, "read_register_array_(%x, %d, , %d) -> %s", reg, count, rx_align, buf.c_str());
@@ -127,7 +128,7 @@ void RC522Spi::pcd_write_register(PcdRegister reg,  ///< The register to write t
     transfer_byte(values[index]);
 
 #ifdef ESPHOME_LOG_HAS_VERY_VERBOSE
-    sprintf(cstrb, " %x", values[index]);
+    buf_append_printf(cstrb, sizeof(cstrb), 0, " %x", values[index]);
     buf.append(cstrb);
 #endif
   }
diff --git a/esphome/components/remote_base/remote_base.cpp b/esphome/components/remote_base/remote_base.cpp
index 53c9c38c7d..b4a549f0be 100644
--- a/esphome/components/remote_base/remote_base.cpp
+++ b/esphome/components/remote_base/remote_base.cpp
@@ -2,8 +2,6 @@
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
-#include <cinttypes>
-
 namespace esphome {
 namespace remote_base {
 
@@ -160,8 +158,8 @@ void RemoteTransmitData::set_data_from_packed_sint32(const uint8_t *data, size_t
   }
 }
 
-bool RemoteTransmitData::set_data_from_base85(const std::string &base85) {
-  return base85_decode_int32_vector(base85, this->data_);
+bool RemoteTransmitData::set_data_from_base64url(const std::string &base64url) {
+  return base64_decode_int32_vector(base64url, this->data_);
 }
 
 /* RemoteTransmitterBase */
diff --git a/esphome/components/remote_base/remote_base.h b/esphome/components/remote_base/remote_base.h
index 2d7642cc31..0cac28506f 100644
--- a/esphome/components/remote_base/remote_base.h
+++ b/esphome/components/remote_base/remote_base.h
@@ -36,11 +36,11 @@ class RemoteTransmitData {
   /// @param len Length of the buffer in bytes
   /// @param count Number of values (for reserve optimization)
   void set_data_from_packed_sint32(const uint8_t *data, size_t len, size_t count);
-  /// Set data from base85-encoded int32 values
-  /// Decodes directly into internal buffer (zero heap allocations)
-  /// @param base85 Base85-encoded string (5 chars per int32 value)
+  /// Set data from base64url-encoded little-endian int32 values
+  /// Base64url is URL-safe: uses '-' instead of '+', '_' instead of '/'
+  /// @param base64url Base64url-encoded string of little-endian int32 values
   /// @return true if successful, false if decode failed or invalid size
-  bool set_data_from_base85(const std::string &base85);
+  bool set_data_from_base64url(const std::string &base64url);
   void reset() {
     this->data_.clear();
     this->carrier_frequency_ = 0;
diff --git a/esphome/components/rf_bridge/rf_bridge.cpp b/esphome/components/rf_bridge/rf_bridge.cpp
index 52ce037dbe..8105767485 100644
--- a/esphome/components/rf_bridge/rf_bridge.cpp
+++ b/esphome/components/rf_bridge/rf_bridge.cpp
@@ -1,6 +1,7 @@
 #include "rf_bridge.h"
-#include "esphome/core/log.h"
 #include "esphome/core/application.h"
+#include "esphome/core/helpers.h"
+#include "esphome/core/log.h"
 #include <cinttypes>
 #include <cstring>
 
@@ -72,9 +73,9 @@ bool RFBridgeComponent::parse_bridge_byte_(uint8_t byte) {
 
       data.length = raw[2];
       data.protocol = raw[3];
-      char next_byte[3];
+      char next_byte[3];  // 2 hex chars + null
       for (uint8_t i = 0; i < data.length - 1; i++) {
-        sprintf(next_byte, "%02X", raw[4 + i]);
+        buf_append_printf(next_byte, sizeof(next_byte), 0, "%02X", raw[4 + i]);
         data.code += next_byte;
       }
 
@@ -90,10 +91,10 @@ bool RFBridgeComponent::parse_bridge_byte_(uint8_t byte) {
 
       uint8_t buckets = raw[2] << 1;
       std::string str;
-      char next_byte[3];
+      char next_byte[3];  // 2 hex chars + null
 
       for (uint32_t i = 0; i <= at; i++) {
-        sprintf(next_byte, "%02X", raw[i]);
+        buf_append_printf(next_byte, sizeof(next_byte), 0, "%02X", raw[i]);
         str += next_byte;
         if ((i > 3) && buckets) {
           buckets--;
diff --git a/esphome/components/select/__init__.py b/esphome/components/select/__init__.py
index c51131a292..84ad591ba1 100644
--- a/esphome/components/select/__init__.py
+++ b/esphome/components/select/__init__.py
@@ -33,7 +33,7 @@ SelectPtr = Select.operator("ptr")
 # Triggers
 SelectStateTrigger = select_ns.class_(
     "SelectStateTrigger",
-    automation.Trigger.template(cg.std_string, cg.size_t),
+    automation.Trigger.template(cg.StringRef, cg.size_t),
 )
 
 # Actions
@@ -100,7 +100,7 @@ async def setup_select_core_(var, config, *, options: list[str]):
     for conf in config.get(CONF_ON_VALUE, []):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
         await automation.build_automation(
-            trigger, [(cg.std_string, "x"), (cg.size_t, "i")], conf
+            trigger, [(cg.StringRef, "x"), (cg.size_t, "i")], conf
         )
 
     if (mqtt_id := config.get(CONF_MQTT_ID)) is not None:
diff --git a/esphome/components/select/automation.h b/esphome/components/select/automation.h
index 81e8a3561d..ffdabd5f7c 100644
--- a/esphome/components/select/automation.h
+++ b/esphome/components/select/automation.h
@@ -6,11 +6,11 @@
 
 namespace esphome::select {
 
-class SelectStateTrigger : public Trigger<std::string, size_t> {
+class SelectStateTrigger : public Trigger<StringRef, size_t> {
  public:
   explicit SelectStateTrigger(Select *parent) : parent_(parent) {
     parent->add_on_state_callback(
-        [this](size_t index) { this->trigger(std::string(this->parent_->option_at(index)), index); });
+        [this](size_t index) { this->trigger(StringRef(this->parent_->option_at(index)), index); });
   }
 
  protected:
diff --git a/esphome/components/sensor/__init__.py b/esphome/components/sensor/__init__.py
index 2ac45a55ac..ebbe0fbccc 100644
--- a/esphome/components/sensor/__init__.py
+++ b/esphome/components/sensor/__init__.py
@@ -9,6 +9,7 @@ from esphome.const import (
     CONF_ABOVE,
     CONF_ACCURACY_DECIMALS,
     CONF_ALPHA,
+    CONF_BASELINE,
     CONF_BELOW,
     CONF_CALIBRATION,
     CONF_DEVICE_CLASS,
@@ -38,7 +39,6 @@ from esphome.const import (
     CONF_TIMEOUT,
     CONF_TO,
     CONF_TRIGGER_ID,
-    CONF_TYPE,
     CONF_UNIT_OF_MEASUREMENT,
     CONF_VALUE,
     CONF_WEB_SERVER,
@@ -107,7 +107,7 @@ from esphome.const import (
 )
 from esphome.core import CORE, CoroPriority, coroutine_with_priority
 from esphome.core.entity_helpers import entity_duplicate_validator, setup_entity
-from esphome.cpp_generator import MockObjClass
+from esphome.cpp_generator import MockObj, MockObjClass
 from esphome.util import Registry
 
 CODEOWNERS = ["@esphome/core"]
@@ -574,38 +574,56 @@ async def lambda_filter_to_code(config, filter_id):
     return automation.new_lambda_pvariable(filter_id, lambda_, StatelessLambdaFilter)
 
 
-DELTA_SCHEMA = cv.Schema(
-    {
-        cv.Required(CONF_VALUE): cv.positive_float,
-        cv.Optional(CONF_TYPE, default="absolute"): cv.one_of(
-            "absolute", "percentage", lower=True
-        ),
-    }
+def validate_delta_value(value):
+    if isinstance(value, str) and value.endswith("%"):
+        # Check it's a well-formed percentage, but return the string as-is
+        try:
+            cv.positive_float(value[:-1])
+            return value
+        except cv.Invalid as exc:
+            raise cv.Invalid("Malformed delta % value") from exc
+    return cv.positive_float(value)
+
+
+# This ideally would be done with `cv.maybe_simple_value` but it doesn't seem to respect the default for min_value.
+DELTA_SCHEMA = cv.Any(
+    cv.All(
+        {
+            # Ideally this would be 'default=float("inf")' but it doesn't translate well to C++
+            cv.Optional(CONF_MAX_VALUE): validate_delta_value,
+            cv.Optional(CONF_MIN_VALUE, default="0.0"): validate_delta_value,
+            cv.Optional(CONF_BASELINE): cv.templatable(cv.float_),
+        },
+        cv.has_at_least_one_key(CONF_MAX_VALUE, CONF_MIN_VALUE),
+    ),
+    validate_delta_value,
 )
 
 
-def validate_delta(config):
-    try:
-        value = cv.positive_float(config)
-        return DELTA_SCHEMA({CONF_VALUE: value, CONF_TYPE: "absolute"})
-    except cv.Invalid:
-        pass
-    try:
-        value = cv.percentage(config)
-        return DELTA_SCHEMA({CONF_VALUE: value, CONF_TYPE: "percentage"})
-    except cv.Invalid:
-        pass
-    raise cv.Invalid("Delta filter requires a positive number or percentage value.")
+def _get_delta(value):
+    if isinstance(value, str):
+        assert value.endswith("%")
+        return 0.0, float(value[:-1])
+    return value, 0.0
 
 
-@FILTER_REGISTRY.register("delta", DeltaFilter, cv.Any(DELTA_SCHEMA, validate_delta))
+@FILTER_REGISTRY.register("delta", DeltaFilter, DELTA_SCHEMA)
 async def delta_filter_to_code(config, filter_id):
-    percentage = config[CONF_TYPE] == "percentage"
-    return cg.new_Pvariable(
-        filter_id,
-        config[CONF_VALUE],
-        percentage,
-    )
+    # The config could be just the min_value, or it could be a dict.
+    max = MockObj("std::numeric_limits<float>::infinity()"), 0
+    if isinstance(config, dict):
+        min = _get_delta(config[CONF_MIN_VALUE])
+        if CONF_MAX_VALUE in config:
+            max = _get_delta(config[CONF_MAX_VALUE])
+    else:
+        min = _get_delta(config)
+    var = cg.new_Pvariable(filter_id, *min, *max)
+    if isinstance(config, dict) and (baseline_lambda := config.get(CONF_BASELINE)):
+        baseline = await cg.process_lambda(
+            baseline_lambda, [(float, "x")], return_type=float
+        )
+        cg.add(var.set_baseline(baseline))
+    return var
 
 
 @FILTER_REGISTRY.register("or", OrFilter, validate_filters)
diff --git a/esphome/components/sensor/filter.cpp b/esphome/components/sensor/filter.cpp
index 8450ec4c4e..3adf28748d 100644
--- a/esphome/components/sensor/filter.cpp
+++ b/esphome/components/sensor/filter.cpp
@@ -291,22 +291,27 @@ optional<float> ThrottleWithPriorityFilter::new_value(float value) {
 }
 
 // DeltaFilter
-DeltaFilter::DeltaFilter(float delta, bool percentage_mode)
-    : delta_(delta), current_delta_(delta), last_value_(NAN), percentage_mode_(percentage_mode) {}
+DeltaFilter::DeltaFilter(float min_a0, float min_a1, float max_a0, float max_a1)
+    : min_a0_(min_a0), min_a1_(min_a1), max_a0_(max_a0), max_a1_(max_a1) {}
+
+void DeltaFilter::set_baseline(float (*fn)(float)) { this->baseline_ = fn; }
+
 optional<float> DeltaFilter::new_value(float value) {
-  if (std::isnan(value)) {
-    if (std::isnan(this->last_value_)) {
-      return {};
-    } else {
-      return this->last_value_ = value;
-    }
+  // Always yield the first value.
+  if (std::isnan(this->last_value_)) {
+    this->last_value_ = value;
+    return value;
   }
-  float diff = fabsf(value - this->last_value_);
-  if (std::isnan(this->last_value_) || (diff > 0.0f && diff >= this->current_delta_)) {
-    if (this->percentage_mode_) {
-      this->current_delta_ = fabsf(value * this->delta_);
-    }
-    return this->last_value_ = value;
+  // calculate min and max using the linear equation
+  float ref = this->baseline_(this->last_value_);
+  float min = fabsf(this->min_a0_ + ref * this->min_a1_);
+  float max = fabsf(this->max_a0_ + ref * this->max_a1_);
+  float delta = fabsf(value - ref);
+  // if there is no reference, e.g. for the first value, just accept this one,
+  // otherwise accept only if within range.
+  if (delta > min && delta <= max) {
+    this->last_value_ = value;
+    return value;
   }
   return {};
 }
diff --git a/esphome/components/sensor/filter.h b/esphome/components/sensor/filter.h
index 15c7656a7b..573b916a5d 100644
--- a/esphome/components/sensor/filter.h
+++ b/esphome/components/sensor/filter.h
@@ -452,15 +452,21 @@ class HeartbeatFilter : public Filter, public Component {
 
 class DeltaFilter : public Filter {
  public:
-  explicit DeltaFilter(float delta, bool percentage_mode);
+  explicit DeltaFilter(float min_a0, float min_a1, float max_a0, float max_a1);
+
+  void set_baseline(float (*fn)(float));
 
   optional<float> new_value(float value) override;
 
  protected:
-  float delta_;
-  float current_delta_;
+  // These values represent linear equations for the min and max values but in practice only one of a0 and a1 will be
+  // non-zero Each limit is calculated as fabs(a0 + value * a1)
+
+  float min_a0_, min_a1_, max_a0_, max_a1_;
+  // default baseline is the previous value
+  float (*baseline_)(float) = [](float last_value) { return last_value; };
+
   float last_value_{NAN};
-  bool percentage_mode_;
 };
 
 class OrFilter : public Filter {
diff --git a/esphome/components/shtcx/shtcx.cpp b/esphome/components/shtcx/shtcx.cpp
index 933dd9bde9..aca305b88d 100644
--- a/esphome/components/shtcx/shtcx.cpp
+++ b/esphome/components/shtcx/shtcx.cpp
@@ -13,14 +13,14 @@ static const uint16_t SHTCX_COMMAND_READ_ID_REGISTER = 0xEFC8;
 static const uint16_t SHTCX_COMMAND_SOFT_RESET = 0x805D;
 static const uint16_t SHTCX_COMMAND_POLLING_H = 0x7866;
 
-inline const char *to_string(SHTCXType type) {
+static const LogString *shtcx_type_to_string(SHTCXType type) {
   switch (type) {
     case SHTCX_TYPE_SHTC3:
-      return "SHTC3";
+      return LOG_STR("SHTC3");
     case SHTCX_TYPE_SHTC1:
-      return "SHTC1";
+      return LOG_STR("SHTC1");
     default:
-      return "UNKNOWN";
+      return LOG_STR("UNKNOWN");
   }
 }
 
@@ -52,7 +52,7 @@ void SHTCXComponent::dump_config() {
   ESP_LOGCONFIG(TAG,
                 "SHTCx:\n"
                 "  Model: %s (%04x)",
-                to_string(this->type_), this->sensor_id_);
+                LOG_STR_ARG(shtcx_type_to_string(this->type_)), this->sensor_id_);
   LOG_I2C_DEVICE(this);
   if (this->is_failed()) {
     ESP_LOGE(TAG, ESP_LOG_MSG_COMM_FAIL);
diff --git a/esphome/components/sim800l/sim800l.cpp b/esphome/components/sim800l/sim800l.cpp
index e3edda0e72..251e18648b 100644
--- a/esphome/components/sim800l/sim800l.cpp
+++ b/esphome/components/sim800l/sim800l.cpp
@@ -1,4 +1,5 @@
 #include "sim800l.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 #include <cstring>
 
@@ -50,8 +51,8 @@ void Sim800LComponent::update() {
   } else if (state_ == STATE_RECEIVED_SMS) {
     // Serial Buffer should have flushed.
     // Send cmd to delete received sms
-    char delete_cmd[20];
-    sprintf(delete_cmd, "AT+CMGD=%d", this->parse_index_);
+    char delete_cmd[20];  // "AT+CMGD=" (8) + uint8_t (max 3) + null = 12 <= 20
+    buf_append_printf(delete_cmd, sizeof(delete_cmd), 0, "AT+CMGD=%d", this->parse_index_);
     this->send_cmd_(delete_cmd);
     this->state_ = STATE_CHECK_SMS;
     this->expect_ack_ = true;
diff --git a/esphome/components/sml/sml_parser.cpp b/esphome/components/sml/sml_parser.cpp
index 85e5a2da03..16e37949dc 100644
--- a/esphome/components/sml/sml_parser.cpp
+++ b/esphome/components/sml/sml_parser.cpp
@@ -104,7 +104,10 @@ std::vector<ObisInfo> SmlFile::get_obis_info() {
 std::string bytes_repr(const BytesView &buffer) {
   std::string repr;
   for (auto const value : buffer) {
-    repr += str_sprintf("%02x", value & 0xff);
+    // max 3: 2 hex digits + null
+    char hex_buf[3];
+    snprintf(hex_buf, sizeof(hex_buf), "%02x", static_cast<unsigned int>(value));
+    repr += hex_buf;
   }
   return repr;
 }
@@ -146,7 +149,11 @@ ObisInfo::ObisInfo(const BytesView &server_id, const SmlNode &val_list_entry) :
 }
 
 std::string ObisInfo::code_repr() const {
-  return str_sprintf("%d-%d:%d.%d.%d", this->code[0], this->code[1], this->code[2], this->code[3], this->code[4]);
+  // max 20: "255-255:255.255.255" (19 chars) + null
+  char buf[20];
+  snprintf(buf, sizeof(buf), "%d-%d:%d.%d.%d", this->code[0], this->code[1], this->code[2], this->code[3],
+           this->code[4]);
+  return buf;
 }
 
 }  // namespace sml
diff --git a/esphome/components/sn74hc165/sn74hc165.cpp b/esphome/components/sn74hc165/sn74hc165.cpp
index 718e0b86ed..63b3f98521 100644
--- a/esphome/components/sn74hc165/sn74hc165.cpp
+++ b/esphome/components/sn74hc165/sn74hc165.cpp
@@ -65,7 +65,7 @@ float SN74HC165Component::get_setup_priority() const { return setup_priority::IO
 bool SN74HC165GPIOPin::digital_read() { return this->parent_->digital_read_(this->pin_) != this->inverted_; }
 
 size_t SN74HC165GPIOPin::dump_summary(char *buffer, size_t len) const {
-  return snprintf(buffer, len, "%u via SN74HC165", this->pin_);
+  return buf_append_printf(buffer, len, 0, "%u via SN74HC165", this->pin_);
 }
 
 }  // namespace sn74hc165
diff --git a/esphome/components/sn74hc595/sn74hc595.cpp b/esphome/components/sn74hc595/sn74hc595.cpp
index 6b5c5d9fc4..1bb8c7936d 100644
--- a/esphome/components/sn74hc595/sn74hc595.cpp
+++ b/esphome/components/sn74hc595/sn74hc595.cpp
@@ -94,7 +94,7 @@ void SN74HC595GPIOPin::digital_write(bool value) {
   this->parent_->digital_write_(this->pin_, value != this->inverted_);
 }
 size_t SN74HC595GPIOPin::dump_summary(char *buffer, size_t len) const {
-  return snprintf(buffer, len, "%u via SN74HC595", this->pin_);
+  return buf_append_printf(buffer, len, 0, "%u via SN74HC595", this->pin_);
 }
 
 }  // namespace sn74hc595
diff --git a/esphome/components/socket/socket.cpp b/esphome/components/socket/socket.cpp
index c92e33393b..fd8725b363 100644
--- a/esphome/components/socket/socket.cpp
+++ b/esphome/components/socket/socket.cpp
@@ -46,15 +46,15 @@ static inline const char *esphome_inet_ntop6(const void *addr, char *buf, size_t
 #endif
 
 // Format sockaddr into caller-provided buffer, returns length written (excluding null)
-static size_t format_sockaddr_to(const struct sockaddr_storage &storage, std::span<char, SOCKADDR_STR_LEN> buf) {
-  if (storage.ss_family == AF_INET) {
-    const auto *addr = reinterpret_cast<const struct sockaddr_in *>(&storage);
+size_t format_sockaddr_to(const struct sockaddr *addr_ptr, socklen_t len, std::span<char, SOCKADDR_STR_LEN> buf) {
+  if (addr_ptr->sa_family == AF_INET && len >= sizeof(const struct sockaddr_in)) {
+    const auto *addr = reinterpret_cast<const struct sockaddr_in *>(addr_ptr);
     if (esphome_inet_ntop4(&addr->sin_addr, buf.data(), buf.size()) != nullptr)
       return strlen(buf.data());
   }
 #if USE_NETWORK_IPV6
-  else if (storage.ss_family == AF_INET6) {
-    const auto *addr = reinterpret_cast<const struct sockaddr_in6 *>(&storage);
+  else if (addr_ptr->sa_family == AF_INET6 && len >= sizeof(sockaddr_in6)) {
+    const auto *addr = reinterpret_cast<const struct sockaddr_in6 *>(addr_ptr);
 #ifndef USE_SOCKET_IMPL_LWIP_TCP
     // Format IPv4-mapped IPv6 addresses as regular IPv4 (not supported on ESP8266 raw TCP)
     if (addr->sin6_addr.un.u32_addr[0] == 0 && addr->sin6_addr.un.u32_addr[1] == 0 &&
@@ -78,7 +78,7 @@ size_t Socket::getpeername_to(std::span<char, SOCKADDR_STR_LEN> buf) {
     buf[0] = '\0';
     return 0;
   }
-  return format_sockaddr_to(storage, buf);
+  return format_sockaddr_to(reinterpret_cast<struct sockaddr *>(&storage), len, buf);
 }
 
 size_t Socket::getsockname_to(std::span<char, SOCKADDR_STR_LEN> buf) {
@@ -88,7 +88,7 @@ size_t Socket::getsockname_to(std::span<char, SOCKADDR_STR_LEN> buf) {
     buf[0] = '\0';
     return 0;
   }
-  return format_sockaddr_to(storage, buf);
+  return format_sockaddr_to(reinterpret_cast<struct sockaddr *>(&storage), len, buf);
 }
 
 std::unique_ptr<Socket> socket_ip(int type, int protocol) {
@@ -107,9 +107,9 @@ std::unique_ptr<Socket> socket_ip_loop_monitored(int type, int protocol) {
 #endif /* USE_NETWORK_IPV6 */
 }
 
-socklen_t set_sockaddr(struct sockaddr *addr, socklen_t addrlen, const std::string &ip_address, uint16_t port) {
+socklen_t set_sockaddr(struct sockaddr *addr, socklen_t addrlen, const char *ip_address, uint16_t port) {
 #if USE_NETWORK_IPV6
-  if (ip_address.find(':') != std::string::npos) {
+  if (strchr(ip_address, ':') != nullptr) {
     if (addrlen < sizeof(sockaddr_in6)) {
       errno = EINVAL;
       return 0;
@@ -121,14 +121,14 @@ socklen_t set_sockaddr(struct sockaddr *addr, socklen_t addrlen, const std::stri
 
 #ifdef USE_SOCKET_IMPL_BSD_SOCKETS
     // Use standard inet_pton for BSD sockets
-    if (inet_pton(AF_INET6, ip_address.c_str(), &server->sin6_addr) != 1) {
+    if (inet_pton(AF_INET6, ip_address, &server->sin6_addr) != 1) {
       errno = EINVAL;
       return 0;
     }
 #else
     // Use LWIP-specific functions
     ip6_addr_t ip6;
-    inet6_aton(ip_address.c_str(), &ip6);
+    inet6_aton(ip_address, &ip6);
     memcpy(server->sin6_addr.un.u32_addr, ip6.addr, sizeof(ip6.addr));
 #endif
     return sizeof(sockaddr_in6);
@@ -141,7 +141,7 @@ socklen_t set_sockaddr(struct sockaddr *addr, socklen_t addrlen, const std::stri
   auto *server = reinterpret_cast<sockaddr_in *>(addr);
   memset(server, 0, sizeof(sockaddr_in));
   server->sin_family = AF_INET;
-  server->sin_addr.s_addr = inet_addr(ip_address.c_str());
+  server->sin_addr.s_addr = inet_addr(ip_address);
   server->sin_port = htons(port);
   return sizeof(sockaddr_in);
 }
diff --git a/esphome/components/socket/socket.h b/esphome/components/socket/socket.h
index 9f9f61de85..e8b0948acd 100644
--- a/esphome/components/socket/socket.h
+++ b/esphome/components/socket/socket.h
@@ -87,11 +87,24 @@ std::unique_ptr<Socket> socket_loop_monitored(int domain, int type, int protocol
 std::unique_ptr<Socket> socket_ip_loop_monitored(int type, int protocol);
 
 /// Set a sockaddr to the specified address and port for the IP version used by socket_ip().
-socklen_t set_sockaddr(struct sockaddr *addr, socklen_t addrlen, const std::string &ip_address, uint16_t port);
+/// @param addr Destination sockaddr structure
+/// @param addrlen Size of the addr buffer
+/// @param ip_address Null-terminated IP address string (IPv4 or IPv6)
+/// @param port Port number in host byte order
+/// @return Size of the sockaddr structure used, or 0 on error
+socklen_t set_sockaddr(struct sockaddr *addr, socklen_t addrlen, const char *ip_address, uint16_t port);
+
+/// Convenience overload for std::string (backward compatible).
+inline socklen_t set_sockaddr(struct sockaddr *addr, socklen_t addrlen, const std::string &ip_address, uint16_t port) {
+  return set_sockaddr(addr, addrlen, ip_address.c_str(), port);
+}
 
 /// Set a sockaddr to the any address and specified port for the IP version used by socket_ip().
 socklen_t set_sockaddr_any(struct sockaddr *addr, socklen_t addrlen, uint16_t port);
 
+/// Format sockaddr into caller-provided buffer, returns length written (excluding null)
+size_t format_sockaddr_to(const struct sockaddr *addr_ptr, socklen_t len, std::span<char, SOCKADDR_STR_LEN> buf);
+
 #if defined(USE_ESP8266) && defined(USE_SOCKET_IMPL_LWIP_TCP)
 /// Delay that can be woken early by socket activity.
 /// On ESP8266, lwip callbacks set a flag and call esp_schedule() to wake the delay.
diff --git a/esphome/components/spi/__init__.py b/esphome/components/spi/__init__.py
index e890567abf..931882be8d 100644
--- a/esphome/components/spi/__init__.py
+++ b/esphome/components/spi/__init__.py
@@ -39,6 +39,7 @@ from esphome.const import (
 )
 from esphome.core import CORE, CoroPriority, coroutine_with_priority
 import esphome.final_validate as fv
+from esphome.types import ConfigType
 
 CODEOWNERS = ["@esphome/core", "@clydebarrow"]
 spi_ns = cg.esphome_ns.namespace("spi")
@@ -448,9 +449,13 @@ def spi_device_schema(
     )
 
 
-async def register_spi_device(var, config):
+async def register_spi_device(
+    var: cg.Pvariable, config: ConfigType, write_only: bool = False
+) -> None:
     parent = await cg.get_variable(config[CONF_SPI_ID])
     cg.add(var.set_spi_parent(parent))
+    if write_only:
+        cg.add(var.set_write_only(True))
     if cs_pin := config.get(CONF_CS_PIN):
         pin = await cg.gpio_pin_expression(cs_pin)
         cg.add(var.set_cs_pin(pin))
diff --git a/esphome/components/spi/spi_esp_idf.cpp b/esphome/components/spi/spi_esp_idf.cpp
index a1837fa58d..107b6a3f1a 100644
--- a/esphome/components/spi/spi_esp_idf.cpp
+++ b/esphome/components/spi/spi_esp_idf.cpp
@@ -195,8 +195,11 @@ class SPIDelegateHw : public SPIDelegate {
     config.post_cb = nullptr;
     if (this->bit_order_ == BIT_ORDER_LSB_FIRST)
       config.flags |= SPI_DEVICE_BIT_LSBFIRST;
-    if (this->write_only_)
+    if (this->write_only_) {
       config.flags |= SPI_DEVICE_HALFDUPLEX | SPI_DEVICE_NO_DUMMY;
+      ESP_LOGD(TAG, "SPI device with CS pin %d using half-duplex mode (write-only)",
+               Utility::get_pin_no(this->cs_pin_));
+    }
     esp_err_t const err = spi_bus_add_device(this->channel_, &config, &this->handle_);
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Add device failed - err %X", err);
diff --git a/esphome/components/spi_led_strip/spi_led_strip.cpp b/esphome/components/spi_led_strip/spi_led_strip.cpp
index afb51afe3a..ff8d2e6ee0 100644
--- a/esphome/components/spi_led_strip/spi_led_strip.cpp
+++ b/esphome/components/spi_led_strip/spi_led_strip.cpp
@@ -1,4 +1,5 @@
 #include "spi_led_strip.h"
+#include "esphome/core/helpers.h"
 
 namespace esphome {
 namespace spi_led_strip {
@@ -47,15 +48,14 @@ void SpiLedStrip::dump_config() {
 void SpiLedStrip::write_state(light::LightState *state) {
   if (this->is_failed())
     return;
-  if (ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_VERBOSE) {
-    char strbuf[49];
-    size_t len = std::min(this->buffer_size_, (size_t) (sizeof(strbuf) - 1) / 3);
-    memset(strbuf, 0, sizeof(strbuf));
-    for (size_t i = 0; i != len; i++) {
-      sprintf(strbuf + i * 3, "%02X ", this->buf_[i]);
-    }
+#if ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_VERBOSE
+  {
+    char strbuf[49];  // format_hex_pretty_size(16) = 48, fits 16 bytes
+    size_t len = std::min(this->buffer_size_, (size_t) 16);
+    format_hex_pretty_to(strbuf, sizeof(strbuf), this->buf_, len, ' ');
     esph_log_v(TAG, "write_state: buf = %s", strbuf);
   }
+#endif
   this->enable();
   this->write_array(this->buf_, this->buffer_size_);
   this->disable();
diff --git a/esphome/components/sprinkler/sprinkler.cpp b/esphome/components/sprinkler/sprinkler.cpp
index 2813b4450b..369ee5e6ff 100644
--- a/esphome/components/sprinkler/sprinkler.cpp
+++ b/esphome/components/sprinkler/sprinkler.cpp
@@ -43,13 +43,11 @@ SprinklerControllerSwitch::SprinklerControllerSwitch()
     : turn_on_trigger_(new Trigger<>()), turn_off_trigger_(new Trigger<>()) {}
 
 void SprinklerControllerSwitch::loop() {
-  if (!this->f_.has_value())
-    return;
+  // Loop is only enabled when f_ has a value (see setup())
   auto s = (*this->f_)();
-  if (!s.has_value())
-    return;
-
-  this->publish_state(*s);
+  if (s.has_value()) {
+    this->publish_state(*s);
+  }
 }
 
 void SprinklerControllerSwitch::write_state(bool state) {
@@ -74,7 +72,13 @@ float SprinklerControllerSwitch::get_setup_priority() const { return setup_prior
 Trigger<> *SprinklerControllerSwitch::get_turn_on_trigger() const { return this->turn_on_trigger_; }
 Trigger<> *SprinklerControllerSwitch::get_turn_off_trigger() const { return this->turn_off_trigger_; }
 
-void SprinklerControllerSwitch::setup() { this->state = this->get_initial_state_with_restore_mode().value_or(false); }
+void SprinklerControllerSwitch::setup() {
+  this->state = this->get_initial_state_with_restore_mode().value_or(false);
+  // Disable loop if no state lambda is set - nothing to poll
+  if (!this->f_.has_value()) {
+    this->disable_loop();
+  }
+}
 
 void SprinklerControllerSwitch::dump_config() { LOG_SWITCH("", "Sprinkler Switch", this); }
 
@@ -327,25 +331,32 @@ SprinklerValveOperator *SprinklerValveRunRequest::valve_operator() { return this
 
 SprinklerValveRunRequestOrigin SprinklerValveRunRequest::request_is_from() { return this->origin_; }
 
-Sprinkler::Sprinkler() {}
-Sprinkler::Sprinkler(const std::string &name) {
-  // The `name` is needed to set timers up, hence non-default constructor
-  // replaces `set_name()` method previously existed
-  this->name_ = name;
+Sprinkler::Sprinkler() : Sprinkler("") {}
+Sprinkler::Sprinkler(const char *name) : name_(name) {
+  // The `name` is stored for dump_config logging
   this->timer_.init(2);
-  this->timer_.push_back({this->name_ + "sm", false, 0, 0, std::bind(&Sprinkler::sm_timer_callback_, this)});
-  this->timer_.push_back({this->name_ + "vs", false, 0, 0, std::bind(&Sprinkler::valve_selection_callback_, this)});
+  // Timer names only need to be unique within this component instance
+  this->timer_.push_back({"sm", false, 0, 0, std::bind(&Sprinkler::sm_timer_callback_, this)});
+  this->timer_.push_back({"vs", false, 0, 0, std::bind(&Sprinkler::valve_selection_callback_, this)});
 }
 
-void Sprinkler::setup() { this->all_valves_off_(true); }
+void Sprinkler::setup() {
+  this->all_valves_off_(true);
+  // Start with loop disabled - nothing to do when idle
+  this->disable_loop();
+}
 
 void Sprinkler::loop() {
   for (auto &vo : this->valve_op_) {
     vo.loop();
   }
-  if (this->prev_req_.has_request() && this->prev_req_.has_valve_operator() &&
-      this->prev_req_.valve_operator()->state() == IDLE) {
-    this->prev_req_.reset();
+  if (this->prev_req_.has_request()) {
+    if (this->prev_req_.has_valve_operator() && this->prev_req_.valve_operator()->state() == IDLE) {
+      this->prev_req_.reset();
+    }
+  } else if (this->state_ == IDLE) {
+    // Nothing more to do - disable loop until next activation
+    this->disable_loop();
   }
 }
 
@@ -1333,6 +1344,8 @@ void Sprinkler::start_valve_(SprinklerValveRunRequest *req) {
   if (!this->is_a_valid_valve(req->valve())) {
     return;  // we can't do anything if the valve number isn't valid
   }
+  // Enable loop to monitor valve operator states
+  this->enable_loop();
   for (auto &vo : this->valve_op_) {  // find the first available SprinklerValveOperator, load it and start it up
     if (vo.state() == IDLE) {
       auto run_duration = req->run_duration() ? req->run_duration() : this->valve_run_duration_adjusted(req->valve());
@@ -1575,8 +1588,7 @@ const LogString *Sprinkler::state_as_str_(SprinklerState state) {
 
 void Sprinkler::start_timer_(const SprinklerTimerIndex timer_index) {
   if (this->timer_duration_(timer_index) > 0) {
-    // FixedVector ensures timer_ can't be resized, so .c_str() pointers remain valid
-    this->set_timeout(this->timer_[timer_index].name.c_str(), this->timer_duration_(timer_index),
+    this->set_timeout(this->timer_[timer_index].name, this->timer_duration_(timer_index),
                       this->timer_cbf_(timer_index));
     this->timer_[timer_index].start_time = millis();
     this->timer_[timer_index].active = true;
@@ -1587,7 +1599,7 @@ void Sprinkler::start_timer_(const SprinklerTimerIndex timer_index) {
 
 bool Sprinkler::cancel_timer_(const SprinklerTimerIndex timer_index) {
   this->timer_[timer_index].active = false;
-  return this->cancel_timeout(this->timer_[timer_index].name.c_str());
+  return this->cancel_timeout(this->timer_[timer_index].name);
 }
 
 bool Sprinkler::timer_active_(const SprinklerTimerIndex timer_index) { return this->timer_[timer_index].active; }
@@ -1618,7 +1630,7 @@ void Sprinkler::sm_timer_callback_() {
 }
 
 void Sprinkler::dump_config() {
-  ESP_LOGCONFIG(TAG, "Sprinkler Controller -- %s", this->name_.c_str());
+  ESP_LOGCONFIG(TAG, "Sprinkler Controller -- %s", this->name_);
   if (this->manual_selection_delay_.has_value()) {
     ESP_LOGCONFIG(TAG, "  Manual Selection Delay: %" PRIu32 " seconds", this->manual_selection_delay_.value_or(0));
   }
diff --git a/esphome/components/sprinkler/sprinkler.h b/esphome/components/sprinkler/sprinkler.h
index 273c0e9208..04efa28031 100644
--- a/esphome/components/sprinkler/sprinkler.h
+++ b/esphome/components/sprinkler/sprinkler.h
@@ -11,7 +11,7 @@
 
 namespace esphome::sprinkler {
 
-const std::string MIN_STR = "min";
+inline constexpr const char *MIN_STR = "min";
 
 enum SprinklerState : uint8_t {
   // NOTE: these states are used by both SprinklerValveOperator and Sprinkler (the controller)!
@@ -49,7 +49,7 @@ struct SprinklerQueueItem {
 };
 
 struct SprinklerTimer {
-  const std::string name;
+  const char *name;
   bool active;
   uint32_t time;
   uint32_t start_time;
@@ -176,7 +176,7 @@ class SprinklerValveRunRequest {
 class Sprinkler : public Component {
  public:
   Sprinkler();
-  Sprinkler(const std::string &name);
+  Sprinkler(const char *name);
   void setup() override;
   void loop() override;
   void dump_config() override;
@@ -504,7 +504,7 @@ class Sprinkler : public Component {
   uint32_t start_delay_{0};
   uint32_t stop_delay_{0};
 
-  std::string name_;
+  const char *name_{""};
 
   /// Sprinkler controller state
   SprinklerState state_{IDLE};
diff --git a/esphome/components/ssd1306_spi/display.py b/esphome/components/ssd1306_spi/display.py
index 4af41073d4..26953b4f39 100644
--- a/esphome/components/ssd1306_spi/display.py
+++ b/esphome/components/ssd1306_spi/display.py
@@ -32,7 +32,7 @@ FINAL_VALIDATE_SCHEMA = spi.final_validate_device_schema(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await ssd1306_base.setup_ssd1306(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/ssd1322_spi/display.py b/esphome/components/ssd1322_spi/display.py
index 849e71abee..3d01caf874 100644
--- a/esphome/components/ssd1322_spi/display.py
+++ b/esphome/components/ssd1322_spi/display.py
@@ -32,7 +32,7 @@ FINAL_VALIDATE_SCHEMA = spi.final_validate_device_schema(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await ssd1322_base.setup_ssd1322(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/ssd1325_spi/display.py b/esphome/components/ssd1325_spi/display.py
index e18db33c68..dbb9a14ac2 100644
--- a/esphome/components/ssd1325_spi/display.py
+++ b/esphome/components/ssd1325_spi/display.py
@@ -32,7 +32,7 @@ FINAL_VALIDATE_SCHEMA = spi.final_validate_device_schema(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await ssd1325_base.setup_ssd1325(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/ssd1327_spi/display.py b/esphome/components/ssd1327_spi/display.py
index b622c098ec..f052764a91 100644
--- a/esphome/components/ssd1327_spi/display.py
+++ b/esphome/components/ssd1327_spi/display.py
@@ -32,7 +32,7 @@ FINAL_VALIDATE_SCHEMA = spi.final_validate_device_schema(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await ssd1327_base.setup_ssd1327(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/ssd1331_spi/display.py b/esphome/components/ssd1331_spi/display.py
index 50895b3175..c16780302f 100644
--- a/esphome/components/ssd1331_spi/display.py
+++ b/esphome/components/ssd1331_spi/display.py
@@ -32,7 +32,7 @@ FINAL_VALIDATE_SCHEMA = spi.final_validate_device_schema(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await ssd1331_base.setup_ssd1331(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/ssd1351_spi/display.py b/esphome/components/ssd1351_spi/display.py
index bd7033c3d4..2a6e984029 100644
--- a/esphome/components/ssd1351_spi/display.py
+++ b/esphome/components/ssd1351_spi/display.py
@@ -32,7 +32,7 @@ FINAL_VALIDATE_SCHEMA = spi.final_validate_device_schema(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await ssd1351_base.setup_ssd1351(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/st7567_spi/display.py b/esphome/components/st7567_spi/display.py
index 305aa35024..02cd2c105c 100644
--- a/esphome/components/st7567_spi/display.py
+++ b/esphome/components/st7567_spi/display.py
@@ -32,7 +32,7 @@ FINAL_VALIDATE_SCHEMA = spi.final_validate_device_schema(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await st7567_base.setup_st7567(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/st7701s/display.py b/esphome/components/st7701s/display.py
index 3078158d25..a8b12dfa28 100644
--- a/esphome/components/st7701s/display.py
+++ b/esphome/components/st7701s/display.py
@@ -173,7 +173,7 @@ FINAL_VALIDATE_SCHEMA = spi.final_validate_device_schema(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await display.register_display(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     sequence = []
     for seq in config[CONF_INIT_SEQUENCE]:
diff --git a/esphome/components/st7735/display.py b/esphome/components/st7735/display.py
index 2761214315..9dc69f27ff 100644
--- a/esphome/components/st7735/display.py
+++ b/esphome/components/st7735/display.py
@@ -99,7 +99,7 @@ async def to_code(config):
         config[CONF_INVERT_COLORS],
     )
     await setup_st7735(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/st7789v/display.py b/esphome/components/st7789v/display.py
index 8259eacf2d..c9f4199616 100644
--- a/esphome/components/st7789v/display.py
+++ b/esphome/components/st7789v/display.py
@@ -177,7 +177,7 @@ FINAL_VALIDATE_SCHEMA = spi.final_validate_device_schema(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await display.register_display(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     cg.add(var.set_model_str(config[CONF_MODEL]))
 
diff --git a/esphome/components/st7920/display.py b/esphome/components/st7920/display.py
index de7b2247dd..ef33fac6c6 100644
--- a/esphome/components/st7920/display.py
+++ b/esphome/components/st7920/display.py
@@ -28,7 +28,7 @@ CONFIG_SCHEMA = (
 
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     if CONF_LAMBDA in config:
         lambda_ = await cg.process_lambda(
diff --git a/esphome/components/statsd/statsd.cpp b/esphome/components/statsd/statsd.cpp
index 7729f36858..7d773bc56e 100644
--- a/esphome/components/statsd/statsd.cpp
+++ b/esphome/components/statsd/statsd.cpp
@@ -114,14 +114,22 @@ void StatsdComponent::update() {
     // This implies you can't explicitly set a gauge to a negative number without first setting it to zero.
     if (val < 0) {
       if (this->prefix_) {
-        out.append(str_sprintf("%s.", this->prefix_));
+        out.append(this->prefix_);
+        out.append(".");
       }
-      out.append(str_sprintf("%s:0|g\n", s.name));
+      out.append(s.name);
+      out.append(":0|g\n");
     }
     if (this->prefix_) {
-      out.append(str_sprintf("%s.", this->prefix_));
+      out.append(this->prefix_);
+      out.append(".");
     }
-    out.append(str_sprintf("%s:%f|g\n", s.name, val));
+    out.append(s.name);
+    // Buffer for ":" + value + "|g\n".
+    // %f with -DBL_MAX can produce up to 321 chars, plus ":" and "|g\n" (4) + null = 326
+    char val_buf[330];
+    buf_append_printf(val_buf, sizeof(val_buf), 0, ":%f|g\n", val);
+    out.append(val_buf);
 
     if (out.length() > SEND_THRESHOLD) {
       this->send_(&out);
diff --git a/esphome/components/status/binary_sensor.py b/esphome/components/status/binary_sensor.py
index c1a4a52ce2..f0c7c87e17 100644
--- a/esphome/components/status/binary_sensor.py
+++ b/esphome/components/status/binary_sensor.py
@@ -7,14 +7,14 @@ DEPENDENCIES = ["network"]
 
 status_ns = cg.esphome_ns.namespace("status")
 StatusBinarySensor = status_ns.class_(
-    "StatusBinarySensor", binary_sensor.BinarySensor, cg.Component
+    "StatusBinarySensor", binary_sensor.BinarySensor, cg.PollingComponent
 )
 
 CONFIG_SCHEMA = binary_sensor.binary_sensor_schema(
     StatusBinarySensor,
     device_class=DEVICE_CLASS_CONNECTIVITY,
     entity_category=ENTITY_CATEGORY_DIAGNOSTIC,
-).extend(cv.COMPONENT_SCHEMA)
+).extend(cv.polling_component_schema("1s"))
 
 
 async def to_code(config):
diff --git a/esphome/components/status/status_binary_sensor.cpp b/esphome/components/status/status_binary_sensor.cpp
index 1795a9c41b..2c95be8569 100644
--- a/esphome/components/status/status_binary_sensor.cpp
+++ b/esphome/components/status/status_binary_sensor.cpp
@@ -10,12 +10,11 @@
 #include "esphome/components/api/api_server.h"
 #endif
 
-namespace esphome {
-namespace status {
+namespace esphome::status {
 
 static const char *const TAG = "status";
 
-void StatusBinarySensor::loop() {
+void StatusBinarySensor::update() {
   bool status = network::is_connected();
 #ifdef USE_MQTT
   if (mqtt::global_mqtt_client != nullptr) {
@@ -33,5 +32,4 @@ void StatusBinarySensor::loop() {
 void StatusBinarySensor::setup() { this->publish_initial_state(false); }
 void StatusBinarySensor::dump_config() { LOG_BINARY_SENSOR("", "Status Binary Sensor", this); }
 
-}  // namespace status
-}  // namespace esphome
+}  // namespace esphome::status
diff --git a/esphome/components/status/status_binary_sensor.h b/esphome/components/status/status_binary_sensor.h
index feda8b6328..7e8c31d741 100644
--- a/esphome/components/status/status_binary_sensor.h
+++ b/esphome/components/status/status_binary_sensor.h
@@ -3,12 +3,11 @@
 #include "esphome/core/component.h"
 #include "esphome/components/binary_sensor/binary_sensor.h"
 
-namespace esphome {
-namespace status {
+namespace esphome::status {
 
-class StatusBinarySensor : public binary_sensor::BinarySensor, public Component {
+class StatusBinarySensor : public binary_sensor::BinarySensor, public PollingComponent {
  public:
-  void loop() override;
+  void update() override;
 
   void setup() override;
   void dump_config() override;
@@ -16,5 +15,4 @@ class StatusBinarySensor : public binary_sensor::BinarySensor, public Component
   bool is_status_binary_sensor() const override { return true; }
 };
 
-}  // namespace status
-}  // namespace esphome
+}  // namespace esphome::status
diff --git a/esphome/components/sun/text_sensor/sun_text_sensor.h b/esphome/components/sun/text_sensor/sun_text_sensor.h
index 9345a32223..c3b60ffd65 100644
--- a/esphome/components/sun/text_sensor/sun_text_sensor.h
+++ b/esphome/components/sun/text_sensor/sun_text_sensor.h
@@ -14,7 +14,9 @@ class SunTextSensor : public text_sensor::TextSensor, public PollingComponent {
   void set_parent(Sun *parent) { parent_ = parent; }
   void set_elevation(double elevation) { elevation_ = elevation; }
   void set_sunrise(bool sunrise) { sunrise_ = sunrise; }
-  void set_format(const std::string &format) { format_ = format; }
+  void set_format(const char *format) { this->format_ = format; }
+  /// Prevent accidental use of std::string which would dangle
+  void set_format(const std::string &format) = delete;
 
   void update() override {
     optional<ESPTime> res;
@@ -29,14 +31,14 @@ class SunTextSensor : public text_sensor::TextSensor, public PollingComponent {
     }
 
     char buf[ESPTime::STRFTIME_BUFFER_SIZE];
-    size_t len = res->strftime_to(buf, this->format_.c_str());
+    size_t len = res->strftime_to(buf, this->format_);
     this->publish_state(buf, len);
   }
 
   void dump_config() override;
 
  protected:
-  std::string format_{};
+  const char *format_{nullptr};
   Sun *parent_;
   double elevation_;
   bool sunrise_;
diff --git a/esphome/components/sx1509/sx1509_gpio_pin.cpp b/esphome/components/sx1509/sx1509_gpio_pin.cpp
index 41a99eba4b..a7e5d0514d 100644
--- a/esphome/components/sx1509/sx1509_gpio_pin.cpp
+++ b/esphome/components/sx1509/sx1509_gpio_pin.cpp
@@ -13,7 +13,7 @@ void SX1509GPIOPin::pin_mode(gpio::Flags flags) { this->parent_->pin_mode(this->
 bool SX1509GPIOPin::digital_read() { return this->parent_->digital_read(this->pin_) != this->inverted_; }
 void SX1509GPIOPin::digital_write(bool value) { this->parent_->digital_write(this->pin_, value != this->inverted_); }
 size_t SX1509GPIOPin::dump_summary(char *buffer, size_t len) const {
-  return snprintf(buffer, len, "%u via sx1509", this->pin_);
+  return buf_append_printf(buffer, len, 0, "%u via sx1509", this->pin_);
 }
 
 }  // namespace sx1509
diff --git a/esphome/components/syslog/esphome_syslog.cpp b/esphome/components/syslog/esphome_syslog.cpp
index 83ad6b2720..376de54db4 100644
--- a/esphome/components/syslog/esphome_syslog.cpp
+++ b/esphome/components/syslog/esphome_syslog.cpp
@@ -47,29 +47,27 @@ void Syslog::log_(const int level, const char *tag, const char *message, size_t
   size_t remaining = sizeof(packet);
 
   // Write PRI - abort if this fails as packet would be malformed
-  int ret = snprintf(packet, remaining, "<%d>", pri);
-  if (ret <= 0 || static_cast<size_t>(ret) >= remaining) {
-    return;
+  offset = buf_append_printf(packet, sizeof(packet), 0, "<%d>", pri);
+  if (offset == 0) {
+    return;  // PRI always produces at least "<0>" (3 chars), so 0 means error
   }
-  offset = ret;
-  remaining -= ret;
+  remaining -= offset;
 
   // Write timestamp directly into packet (RFC 5424: use "-" if time not valid or strftime fails)
   auto now = this->time_->now();
   size_t ts_written = now.is_valid() ? now.strftime(packet + offset, remaining, "%b %e %H:%M:%S") : 0;
   if (ts_written > 0) {
     offset += ts_written;
-    remaining -= ts_written;
   } else if (remaining > 0) {
     packet[offset++] = '-';
-    remaining--;
   }
 
   // Write hostname, tag, and message
-  ret = snprintf(packet + offset, remaining, " %s %s: %.*s", App.get_name().c_str(), tag, (int) len, message);
-  if (ret > 0) {
-    // snprintf returns chars that would be written; clamp to actual buffer space
-    offset += std::min(static_cast<size_t>(ret), remaining > 0 ? remaining - 1 : 0);
+  offset = buf_append_printf(packet, sizeof(packet), offset, " %s %s: %.*s", App.get_name().c_str(), tag, (int) len,
+                             message);
+  // Clamp to exclude null terminator position if buffer was filled
+  if (offset >= sizeof(packet)) {
+    offset = sizeof(packet) - 1;
   }
 
   if (offset > 0) {
diff --git a/esphome/components/tca9555/tca9555.cpp b/esphome/components/tca9555/tca9555.cpp
index 376de6a370..79c5253898 100644
--- a/esphome/components/tca9555/tca9555.cpp
+++ b/esphome/components/tca9555/tca9555.cpp
@@ -139,7 +139,7 @@ void TCA9555GPIOPin::pin_mode(gpio::Flags flags) { this->parent_->pin_mode(this-
 bool TCA9555GPIOPin::digital_read() { return this->parent_->digital_read(this->pin_) != this->inverted_; }
 void TCA9555GPIOPin::digital_write(bool value) { this->parent_->digital_write(this->pin_, value != this->inverted_); }
 size_t TCA9555GPIOPin::dump_summary(char *buffer, size_t len) const {
-  return snprintf(buffer, len, "%u via TCA9555", this->pin_);
+  return buf_append_printf(buffer, len, 0, "%u via TCA9555", this->pin_);
 }
 
 }  // namespace tca9555
diff --git a/esphome/components/template/alarm_control_panel/__init__.py b/esphome/components/template/alarm_control_panel/__init__.py
index 256c7f276a..59624a5f53 100644
--- a/esphome/components/template/alarm_control_panel/__init__.py
+++ b/esphome/components/template/alarm_control_panel/__init__.py
@@ -118,8 +118,7 @@ async def to_code(config):
     var = await alarm_control_panel.new_alarm_control_panel(config)
     await cg.register_component(var, config)
     if CONF_CODES in config:
-        for acode in config[CONF_CODES]:
-            cg.add(var.add_code(acode))
+        cg.add(var.set_codes(config[CONF_CODES]))
         if CONF_REQUIRES_CODE_TO_ARM in config:
             cg.add(var.set_requires_code_to_arm(config[CONF_REQUIRES_CODE_TO_ARM]))
 
diff --git a/esphome/components/template/alarm_control_panel/template_alarm_control_panel.cpp b/esphome/components/template/alarm_control_panel/template_alarm_control_panel.cpp
index 50e43da8d5..028d6f0879 100644
--- a/esphome/components/template/alarm_control_panel/template_alarm_control_panel.cpp
+++ b/esphome/components/template/alarm_control_panel/template_alarm_control_panel.cpp
@@ -206,7 +206,13 @@ bool TemplateAlarmControlPanel::is_code_valid_(optional<std::string> code) {
   if (!this->codes_.empty()) {
     if (code.has_value()) {
       ESP_LOGVV(TAG, "Checking code: %s", code.value().c_str());
-      return (std::count(this->codes_.begin(), this->codes_.end(), code.value()) == 1);
+      // Use strcmp for const char* comparison
+      const char *code_cstr = code.value().c_str();
+      for (const char *stored_code : this->codes_) {
+        if (strcmp(stored_code, code_cstr) == 0)
+          return true;
+      }
+      return false;
     }
     ESP_LOGD(TAG, "No code provided");
     return false;
diff --git a/esphome/components/template/alarm_control_panel/template_alarm_control_panel.h b/esphome/components/template/alarm_control_panel/template_alarm_control_panel.h
index 2038d8f1b0..df3b64fb6e 100644
--- a/esphome/components/template/alarm_control_panel/template_alarm_control_panel.h
+++ b/esphome/components/template/alarm_control_panel/template_alarm_control_panel.h
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <cinttypes>
+#include <cstring>
 #include <vector>
 
 #include "esphome/core/automation.h"
@@ -86,11 +87,14 @@ class TemplateAlarmControlPanel final : public alarm_control_panel::AlarmControl
                   AlarmSensorType type = ALARM_SENSOR_TYPE_DELAYED);
 #endif
 
-  /** add a code
+  /** Set the codes (from initializer list).
    *
-   * @param code The code
+   * @param codes The list of valid codes
    */
-  void add_code(const std::string &code) { this->codes_.push_back(code); }
+  void set_codes(std::initializer_list<const char *> codes) { this->codes_ = codes; }
+
+  // Deleted overload to catch incorrect std::string usage at compile time
+  void set_codes(std::initializer_list<std::string> codes) = delete;
 
   /** set requires a code to arm
    *
@@ -155,8 +159,8 @@ class TemplateAlarmControlPanel final : public alarm_control_panel::AlarmControl
   uint32_t pending_time_;
   // the time in trigger
   uint32_t trigger_time_;
-  // a list of codes
-  std::vector<std::string> codes_;
+  // a list of codes (const char* pointers to string literals in flash)
+  FixedVector<const char *> codes_;
   // requires a code to arm
   bool requires_code_to_arm_ = false;
   bool supports_arm_home_ = false;
diff --git a/esphome/components/template/select/__init__.py b/esphome/components/template/select/__init__.py
index 0e9c240547..574f1f5fb7 100644
--- a/esphome/components/template/select/__init__.py
+++ b/esphome/components/template/select/__init__.py
@@ -88,5 +88,5 @@ async def to_code(config):
 
     if CONF_SET_ACTION in config:
         await automation.build_automation(
-            var.get_set_trigger(), [(cg.std_string, "x")], config[CONF_SET_ACTION]
+            var.get_set_trigger(), [(cg.StringRef, "x")], config[CONF_SET_ACTION]
         )
diff --git a/esphome/components/template/select/template_select.cpp b/esphome/components/template/select/template_select.cpp
index 9d2df0956b..818abfc1d7 100644
--- a/esphome/components/template/select/template_select.cpp
+++ b/esphome/components/template/select/template_select.cpp
@@ -41,7 +41,7 @@ void TemplateSelect::update() {
 }
 
 void TemplateSelect::control(size_t index) {
-  this->set_trigger_->trigger(std::string(this->option_at(index)));
+  this->set_trigger_->trigger(StringRef(this->option_at(index)));
 
   if (this->optimistic_)
     this->publish_state(index);
diff --git a/esphome/components/template/select/template_select.h b/esphome/components/template/select/template_select.h
index 2757c51405..114d25b9ce 100644
--- a/esphome/components/template/select/template_select.h
+++ b/esphome/components/template/select/template_select.h
@@ -4,6 +4,7 @@
 #include "esphome/core/automation.h"
 #include "esphome/core/component.h"
 #include "esphome/core/preferences.h"
+#include "esphome/core/string_ref.h"
 #include "esphome/core/template_lambda.h"
 
 namespace esphome::template_ {
@@ -17,7 +18,7 @@ class TemplateSelect final : public select::Select, public PollingComponent {
   void dump_config() override;
   float get_setup_priority() const override { return setup_priority::HARDWARE; }
 
-  Trigger<std::string> *get_set_trigger() const { return this->set_trigger_; }
+  Trigger<StringRef> *get_set_trigger() const { return this->set_trigger_; }
   void set_optimistic(bool optimistic) { this->optimistic_ = optimistic; }
   void set_initial_option_index(size_t initial_option_index) { this->initial_option_index_ = initial_option_index; }
   void set_restore_value(bool restore_value) { this->restore_value_ = restore_value; }
@@ -27,7 +28,7 @@ class TemplateSelect final : public select::Select, public PollingComponent {
   bool optimistic_ = false;
   size_t initial_option_index_{0};
   bool restore_value_ = false;
-  Trigger<std::string> *set_trigger_ = new Trigger<std::string>();
+  Trigger<StringRef> *set_trigger_ = new Trigger<StringRef>();
   TemplateLambda<std::string> f_;
 
   ESPPreferenceObject pref_;
diff --git a/esphome/components/template/text/template_text.cpp b/esphome/components/template/text/template_text.cpp
index 32ed8f047b..5acbb6e15a 100644
--- a/esphome/components/template/text/template_text.cpp
+++ b/esphome/components/template/text/template_text.cpp
@@ -8,16 +8,23 @@ static const char *const TAG = "template.text";
 void TemplateText::setup() {
   if (this->f_.has_value())
     return;
-  std::string value = this->initial_value_;
-  if (!this->pref_) {
-    ESP_LOGD(TAG, "State from initial: %s", value.c_str());
-  } else {
-    uint32_t key = this->get_preference_hash();
-    key += this->traits.get_min_length() << 2;
-    key += this->traits.get_max_length() << 4;
-    key += fnv1_hash(this->traits.get_pattern_c_str()) << 6;
-    this->pref_->setup(key, value);
+
+  if (this->pref_ == nullptr) {
+    // No restore - use const char* directly, no heap allocation needed
+    if (this->initial_value_ != nullptr && this->initial_value_[0] != '\0') {
+      ESP_LOGD(TAG, "State from initial: %s", this->initial_value_);
+      this->publish_state(this->initial_value_);
+    }
+    return;
   }
+
+  // Need std::string for pref_->setup() to fill from flash
+  std::string value{this->initial_value_ != nullptr ? this->initial_value_ : ""};
+  uint32_t key = this->get_preference_hash();
+  key += this->traits.get_min_length() << 2;
+  key += this->traits.get_max_length() << 4;
+  key += fnv1_hash(this->traits.get_pattern_c_str()) << 6;
+  this->pref_->setup(key, value);
   if (!value.empty())
     this->publish_state(value);
 }
diff --git a/esphome/components/template/text/template_text.h b/esphome/components/template/text/template_text.h
index 178b410ed2..e5e5e4f4a8 100644
--- a/esphome/components/template/text/template_text.h
+++ b/esphome/components/template/text/template_text.h
@@ -70,13 +70,15 @@ class TemplateText final : public text::Text, public PollingComponent {
 
   Trigger<std::string> *get_set_trigger() const { return this->set_trigger_; }
   void set_optimistic(bool optimistic) { this->optimistic_ = optimistic; }
-  void set_initial_value(const std::string &initial_value) { this->initial_value_ = initial_value; }
+  void set_initial_value(const char *initial_value) { this->initial_value_ = initial_value; }
+  /// Prevent accidental use of std::string which would dangle
+  void set_initial_value(const std::string &initial_value) = delete;
   void set_value_saver(TemplateTextSaverBase *restore_value_saver) { this->pref_ = restore_value_saver; }
 
  protected:
   void control(const std::string &value) override;
   bool optimistic_ = false;
-  std::string initial_value_;
+  const char *initial_value_{nullptr};
   Trigger<std::string> *set_trigger_ = new Trigger<std::string>();
   TemplateLambda<std::string> f_{};
 
diff --git a/esphome/components/tormatic/tormatic_protocol.h b/esphome/components/tormatic/tormatic_protocol.h
index e26535e985..057713b884 100644
--- a/esphome/components/tormatic/tormatic_protocol.h
+++ b/esphome/components/tormatic/tormatic_protocol.h
@@ -55,6 +55,7 @@ enum MessageType : uint16_t {
   COMMAND = 0x0106,
 };
 
+// Max string length: 7 ("Unknown"/"Command"). Update print() buffer sizes if adding longer strings.
 inline const char *message_type_to_str(MessageType t) {
   switch (t) {
     case STATUS:
@@ -83,7 +84,11 @@ struct MessageHeader {
   }
 
   std::string print() {
-    return str_sprintf("MessageHeader: seq %d, len %d, type %s", this->seq, this->len, message_type_to_str(this->type));
+    // 64 bytes: "MessageHeader: seq " + uint16 + ", len " + uint32 + ", type " + type + safety margin
+    char buf[64];
+    buf_append_printf(buf, sizeof(buf), 0, "MessageHeader: seq %d, len %d, type %s", this->seq, this->len,
+                      message_type_to_str(this->type));
+    return buf;
   }
 
   void byteswap() {
@@ -131,6 +136,7 @@ inline CoverOperation gate_status_to_cover_operation(GateStatus s) {
   return COVER_OPERATION_IDLE;
 }
 
+// Max string length: 11 ("Ventilating"). Update print() buffer sizes if adding longer strings.
 inline const char *gate_status_to_str(GateStatus s) {
   switch (s) {
     case PAUSED:
@@ -170,7 +176,12 @@ struct StatusReply {
   GateStatus state;
   uint8_t trailer = 0x0;
 
-  std::string print() { return str_sprintf("StatusReply: state %s", gate_status_to_str(this->state)); }
+  std::string print() {
+    // 48 bytes: "StatusReply: state " (19) + state (11) + safety margin
+    char buf[48];
+    buf_append_printf(buf, sizeof(buf), 0, "StatusReply: state %s", gate_status_to_str(this->state));
+    return buf;
+  }
 
   void byteswap(){};
 } __attribute__((packed));
@@ -202,7 +213,12 @@ struct CommandRequestReply {
   CommandRequestReply() = default;
   CommandRequestReply(GateStatus state) { this->state = state; }
 
-  std::string print() { return str_sprintf("CommandRequestReply: state %s", gate_status_to_str(this->state)); }
+  std::string print() {
+    // 56 bytes: "CommandRequestReply: state " (27) + state (11) + safety margin
+    char buf[56];
+    buf_append_printf(buf, sizeof(buf), 0, "CommandRequestReply: state %s", gate_status_to_str(this->state));
+    return buf;
+  }
 
   void byteswap() { this->type = convert_big_endian(this->type); }
 } __attribute__((packed));
diff --git a/esphome/components/toshiba/toshiba.cpp b/esphome/components/toshiba/toshiba.cpp
index 5efa70d6b4..7b5e78af52 100644
--- a/esphome/components/toshiba/toshiba.cpp
+++ b/esphome/components/toshiba/toshiba.cpp
@@ -1,5 +1,6 @@
 #include "toshiba.h"
 #include "esphome/components/remote_base/toshiba_ac_protocol.h"
+#include "esphome/core/helpers.h"
 
 #include <vector>
 
@@ -427,10 +428,17 @@ void ToshibaClimate::setup() {
   // Never send nan to HA
   if (std::isnan(this->target_temperature))
     this->target_temperature = 24;
+#if ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_VERBOSE
   // Log final state for debugging HA errors
-  ESP_LOGV(TAG, "Setup complete - Mode: %d, Fan: %s, Swing: %d, Temp: %.1f", static_cast<int>(this->mode),
-           this->fan_mode.has_value() ? std::to_string(static_cast<int>(this->fan_mode.value())).c_str() : "NONE",
+  const char *fan_mode_str = "NONE";
+  char fan_mode_buf[4];  // max 3 digits for fan mode enum + null
+  if (this->fan_mode.has_value()) {
+    buf_append_printf(fan_mode_buf, sizeof(fan_mode_buf), 0, "%d", static_cast<int>(this->fan_mode.value()));
+    fan_mode_str = fan_mode_buf;
+  }
+  ESP_LOGV(TAG, "Setup complete - Mode: %d, Fan: %s, Swing: %d, Temp: %.1f", static_cast<int>(this->mode), fan_mode_str,
            static_cast<int>(this->swing_mode), this->target_temperature);
+#endif
 }
 
 void ToshibaClimate::transmit_state() {
diff --git a/esphome/components/tuya/light/tuya_light.cpp b/esphome/components/tuya/light/tuya_light.cpp
index c487f9f50b..097b3c1af8 100644
--- a/esphome/components/tuya/light/tuya_light.cpp
+++ b/esphome/components/tuya/light/tuya_light.cpp
@@ -191,7 +191,7 @@ void TuyaLight::write_state(light::LightState *state) {
       case TuyaColorType::RGB: {
         char buffer[7];
         const char *format_str = this->color_type_lowercase_ ? "%02x%02x%02x" : "%02X%02X%02X";
-        sprintf(buffer, format_str, int(red * 255), int(green * 255), int(blue * 255));
+        snprintf(buffer, sizeof(buffer), format_str, int(red * 255), int(green * 255), int(blue * 255));
         color_value = buffer;
         break;
       }
@@ -201,7 +201,7 @@ void TuyaLight::write_state(light::LightState *state) {
         rgb_to_hsv(red, green, blue, hue, saturation, value);
         char buffer[13];
         const char *format_str = this->color_type_lowercase_ ? "%04x%04x%04x" : "%04X%04X%04X";
-        sprintf(buffer, format_str, hue, int(saturation * 1000), int(value * 1000));
+        snprintf(buffer, sizeof(buffer), format_str, hue, int(saturation * 1000), int(value * 1000));
         color_value = buffer;
         break;
       }
@@ -211,8 +211,8 @@ void TuyaLight::write_state(light::LightState *state) {
         rgb_to_hsv(red, green, blue, hue, saturation, value);
         char buffer[15];
         const char *format_str = this->color_type_lowercase_ ? "%02x%02x%02x%04x%02x%02x" : "%02X%02X%02X%04X%02X%02X";
-        sprintf(buffer, format_str, int(red * 255), int(green * 255), int(blue * 255), hue, int(saturation * 255),
-                int(value * 255));
+        snprintf(buffer, sizeof(buffer), format_str, int(red * 255), int(green * 255), int(blue * 255), hue,
+                 int(saturation * 255), int(value * 255));
         color_value = buffer;
         break;
       }
diff --git a/esphome/components/tuya/text_sensor/tuya_text_sensor.cpp b/esphome/components/tuya/text_sensor/tuya_text_sensor.cpp
index 36b6d630ae..b15fb6f85a 100644
--- a/esphome/components/tuya/text_sensor/tuya_text_sensor.cpp
+++ b/esphome/components/tuya/text_sensor/tuya_text_sensor.cpp
@@ -24,7 +24,7 @@ void TuyaTextSensor::setup() {
       }
       case TuyaDatapointType::ENUM: {
         char buf[4];  // uint8_t max is 3 digits + null
-        snprintf(buf, sizeof(buf), "%u", datapoint.value_enum);
+        buf_append_printf(buf, sizeof(buf), 0, "%u", datapoint.value_enum);
         ESP_LOGD(TAG, "MCU reported text sensor %u is: %s", datapoint.id, buf);
         this->publish_state(buf);
         break;
diff --git a/esphome/components/uart/uart_debugger.cpp b/esphome/components/uart/uart_debugger.cpp
index b51a57d68e..5490154d01 100644
--- a/esphome/components/uart/uart_debugger.cpp
+++ b/esphome/components/uart/uart_debugger.cpp
@@ -107,7 +107,7 @@ void UARTDebug::log_hex(UARTDirection direction, std::vector<uint8_t> bytes, uin
     if (i > 0) {
       res += separator;
     }
-    sprintf(buf, "%02X", bytes[i]);
+    buf_append_printf(buf, sizeof(buf), 0, "%02X", bytes[i]);
     res += buf;
   }
   ESP_LOGD(TAG, "%s", res.c_str());
@@ -147,7 +147,7 @@ void UARTDebug::log_string(UARTDirection direction, std::vector<uint8_t> bytes)
     } else if (bytes[i] == 92) {
       res += "\\\\";
     } else if (bytes[i] < 32 || bytes[i] > 127) {
-      sprintf(buf, "\\x%02X", bytes[i]);
+      buf_append_printf(buf, sizeof(buf), 0, "\\x%02X", bytes[i]);
       res += buf;
     } else {
       res += bytes[i];
@@ -166,11 +166,13 @@ void UARTDebug::log_int(UARTDirection direction, std::vector<uint8_t> bytes, uin
   } else {
     res += ">>> ";
   }
+  char buf[4];  // max 3 digits for uint8_t (255) + null
   for (size_t i = 0; i < len; i++) {
     if (i > 0) {
       res += separator;
     }
-    res += to_string(bytes[i]);
+    buf_append_printf(buf, sizeof(buf), 0, "%u", bytes[i]);
+    res += buf;
   }
   ESP_LOGD(TAG, "%s", res.c_str());
   delay(10);
@@ -189,7 +191,7 @@ void UARTDebug::log_binary(UARTDirection direction, std::vector<uint8_t> bytes,
     if (i > 0) {
       res += separator;
     }
-    sprintf(buf, "0b" BYTE_TO_BINARY_PATTERN " (0x%02X)", BYTE_TO_BINARY(bytes[i]), bytes[i]);
+    buf_append_printf(buf, sizeof(buf), 0, "0b" BYTE_TO_BINARY_PATTERN " (0x%02X)", BYTE_TO_BINARY(bytes[i]), bytes[i]);
     res += buf;
   }
   ESP_LOGD(TAG, "%s", res.c_str());
diff --git a/esphome/components/udp/__init__.py b/esphome/components/udp/__init__.py
index 69abf4b989..9be196d420 100644
--- a/esphome/components/udp/__init__.py
+++ b/esphome/components/udp/__init__.py
@@ -108,8 +108,7 @@ async def to_code(config):
         cg.add(var.set_broadcast_port(conf_port[CONF_BROADCAST_PORT]))
     if (listen_address := str(config[CONF_LISTEN_ADDRESS])) != "255.255.255.255":
         cg.add(var.set_listen_address(listen_address))
-    for address in config[CONF_ADDRESSES]:
-        cg.add(var.add_address(str(address)))
+    cg.add(var.set_addresses([str(addr) for addr in config[CONF_ADDRESSES]]))
     if on_receive := config.get(CONF_ON_RECEIVE):
         on_receive = on_receive[0]
         trigger = cg.new_Pvariable(on_receive[CONF_TRIGGER_ID])
diff --git a/esphome/components/udp/udp_component.cpp b/esphome/components/udp/udp_component.cpp
index 4474efeb77..947a59dfa9 100644
--- a/esphome/components/udp/udp_component.cpp
+++ b/esphome/components/udp/udp_component.cpp
@@ -5,8 +5,7 @@
 #include "esphome/components/network/util.h"
 #include "udp_component.h"
 
-namespace esphome {
-namespace udp {
+namespace esphome::udp {
 
 static const char *const TAG = "udp";
 
@@ -95,7 +94,7 @@ void UDPComponent::setup() {
   // 8266 and RP2040 `Duino
   for (const auto &address : this->addresses_) {
     auto ipaddr = IPAddress();
-    ipaddr.fromString(address.c_str());
+    ipaddr.fromString(address);
     this->ipaddrs_.push_back(ipaddr);
   }
   if (this->should_listen_)
@@ -130,8 +129,8 @@ void UDPComponent::dump_config() {
                 "  Listen Port: %u\n"
                 "  Broadcast Port: %u",
                 this->listen_port_, this->broadcast_port_);
-  for (const auto &address : this->addresses_)
-    ESP_LOGCONFIG(TAG, "  Address: %s", address.c_str());
+  for (const char *address : this->addresses_)
+    ESP_LOGCONFIG(TAG, "  Address: %s", address);
   if (this->listen_address_.has_value()) {
     char addr_buf[network::IP_ADDRESS_BUFFER_SIZE];
     ESP_LOGCONFIG(TAG, "  Listen address: %s", this->listen_address_.value().str_to(addr_buf));
@@ -162,7 +161,6 @@ void UDPComponent::send_packet(const uint8_t *data, size_t size) {
   }
 #endif
 }
-}  // namespace udp
-}  // namespace esphome
+}  // namespace esphome::udp
 
 #endif
diff --git a/esphome/components/udp/udp_component.h b/esphome/components/udp/udp_component.h
index 065789ae28..9967e4dbbb 100644
--- a/esphome/components/udp/udp_component.h
+++ b/esphome/components/udp/udp_component.h
@@ -2,6 +2,7 @@
 
 #include "esphome/core/defines.h"
 #ifdef USE_NETWORK
+#include "esphome/core/helpers.h"
 #include "esphome/components/network/ip_address.h"
 #if defined(USE_SOCKET_IMPL_BSD_SOCKETS) || defined(USE_SOCKET_IMPL_LWIP_SOCKETS)
 #include "esphome/components/socket/socket.h"
@@ -9,15 +10,17 @@
 #ifdef USE_SOCKET_IMPL_LWIP_TCP
 #include <WiFiUdp.h>
 #endif
+#include <initializer_list>
 #include <vector>
 
-namespace esphome {
-namespace udp {
+namespace esphome::udp {
 
 static const size_t MAX_PACKET_SIZE = 508;
 class UDPComponent : public Component {
  public:
-  void add_address(const char *addr) { this->addresses_.emplace_back(addr); }
+  void set_addresses(std::initializer_list<const char *> addresses) { this->addresses_ = addresses; }
+  /// Prevent accidental use of std::string which would dangle
+  void set_addresses(std::initializer_list<std::string> addresses) = delete;
   void set_listen_address(const char *listen_addr) { this->listen_address_ = network::IPAddress(listen_addr); }
   void set_listen_port(uint16_t port) { this->listen_port_ = port; }
   void set_broadcast_port(uint16_t port) { this->broadcast_port_ = port; }
@@ -49,11 +52,10 @@ class UDPComponent : public Component {
   std::vector<IPAddress> ipaddrs_{};
   WiFiUDP udp_client_{};
 #endif
-  std::vector<std::string> addresses_{};
+  FixedVector<const char *> addresses_{};
 
   optional<network::IPAddress> listen_address_{};
 };
 
-}  // namespace udp
-}  // namespace esphome
+}  // namespace esphome::udp
 #endif
diff --git a/esphome/components/uptime/text_sensor/uptime_text_sensor.cpp b/esphome/components/uptime/text_sensor/uptime_text_sensor.cpp
index b7b3273f39..acd3980a1a 100644
--- a/esphome/components/uptime/text_sensor/uptime_text_sensor.cpp
+++ b/esphome/components/uptime/text_sensor/uptime_text_sensor.cpp
@@ -9,17 +9,12 @@ namespace uptime {
 
 static const char *const TAG = "uptime.sensor";
 
-// Clamp position to valid buffer range when snprintf indicates truncation
-static size_t clamp_buffer_pos(size_t pos, size_t buf_size) { return pos < buf_size ? pos : buf_size - 1; }
-
 static void append_unit(char *buf, size_t buf_size, size_t &pos, const char *separator, unsigned value,
                         const char *label) {
   if (pos > 0) {
-    pos += snprintf(buf + pos, buf_size - pos, "%s", separator);
-    pos = clamp_buffer_pos(pos, buf_size);
+    pos = buf_append_printf(buf, buf_size, pos, "%s", separator);
   }
-  pos += snprintf(buf + pos, buf_size - pos, "%u%s", value, label);
-  pos = clamp_buffer_pos(pos, buf_size);
+  pos = buf_append_printf(buf, buf_size, pos, "%u%s", value, label);
 }
 
 void UptimeTextSensor::setup() {
diff --git a/esphome/components/voice_assistant/voice_assistant.h b/esphome/components/voice_assistant/voice_assistant.h
index b1b3df7bbd..d61a8fbbc1 100644
--- a/esphome/components/voice_assistant/voice_assistant.h
+++ b/esphome/components/voice_assistant/voice_assistant.h
@@ -81,6 +81,8 @@ struct Timer {
              this->id.c_str(), this->name.c_str(), this->total_seconds, this->seconds_left, YESNO(this->is_active));
     return buffer.data();
   }
+  // Remove before 2026.8.0
+  ESPDEPRECATED("Use to_str() instead. Removed in 2026.8.0", "2026.2.0")
   std::string to_string() const {
     char buffer[TO_STR_BUFFER_SIZE];
     return this->to_str(buffer);
diff --git a/esphome/components/waveshare_epaper/display.py b/esphome/components/waveshare_epaper/display.py
index cea0b2be5e..5db7a1fc3d 100644
--- a/esphome/components/waveshare_epaper/display.py
+++ b/esphome/components/waveshare_epaper/display.py
@@ -239,7 +239,7 @@ async def to_code(config):
         raise NotImplementedError()
 
     await display.register_display(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/web_server/list_entities.cpp b/esphome/components/web_server/list_entities.cpp
index 0af9521326..8458298062 100644
--- a/esphome/components/web_server/list_entities.cpp
+++ b/esphome/components/web_server/list_entities.cpp
@@ -143,7 +143,7 @@ bool ListEntitiesIterator::on_water_heater(water_heater::WaterHeater *obj) {
 
 #ifdef USE_INFRARED
 bool ListEntitiesIterator::on_infrared(infrared::Infrared *obj) {
-  // Infrared web_server support not yet implemented - this stub acknowledges the entity
+  this->events_->deferrable_send_state(obj, "state_detail_all", WebServer::infrared_all_json_generator);
   return true;
 }
 #endif
diff --git a/esphome/components/web_server/web_server.cpp b/esphome/components/web_server/web_server.cpp
index cf984ea247..e538a35e8c 100644
--- a/esphome/components/web_server/web_server.cpp
+++ b/esphome/components/web_server/web_server.cpp
@@ -33,6 +33,10 @@
 #include "esphome/components/water_heater/water_heater.h"
 #endif
 
+#ifdef USE_INFRARED
+#include "esphome/components/infrared/infrared.h"
+#endif
+
 #ifdef USE_WEBSERVER_LOCAL
 #if USE_WEBSERVER_VERSION == 2
 #include "server_index_v2.h"
@@ -658,6 +662,24 @@ std::string WebServer::text_sensor_json_(text_sensor::TextSensor *obj, const std
 #endif
 
 #ifdef USE_SWITCH
+enum SwitchAction : uint8_t { SWITCH_ACTION_NONE, SWITCH_ACTION_TOGGLE, SWITCH_ACTION_TURN_ON, SWITCH_ACTION_TURN_OFF };
+
+static void execute_switch_action(switch_::Switch *obj, SwitchAction action) {
+  switch (action) {
+    case SWITCH_ACTION_TOGGLE:
+      obj->toggle();
+      break;
+    case SWITCH_ACTION_TURN_ON:
+      obj->turn_on();
+      break;
+    case SWITCH_ACTION_TURN_OFF:
+      obj->turn_off();
+      break;
+    default:
+      break;
+  }
+}
+
 void WebServer::on_switch_update(switch_::Switch *obj) {
   if (!this->include_internal_ && obj->is_internal())
     return;
@@ -676,34 +698,22 @@ void WebServer::handle_switch_request(AsyncWebServerRequest *request, const UrlM
       return;
     }
 
-    // Handle action methods with single defer and response
-    enum SwitchAction { NONE, TOGGLE, TURN_ON, TURN_OFF };
-    SwitchAction action = NONE;
+    SwitchAction action = SWITCH_ACTION_NONE;
 
     if (match.method_equals(ESPHOME_F("toggle"))) {
-      action = TOGGLE;
+      action = SWITCH_ACTION_TOGGLE;
     } else if (match.method_equals(ESPHOME_F("turn_on"))) {
-      action = TURN_ON;
+      action = SWITCH_ACTION_TURN_ON;
     } else if (match.method_equals(ESPHOME_F("turn_off"))) {
-      action = TURN_OFF;
+      action = SWITCH_ACTION_TURN_OFF;
     }
 
-    if (action != NONE) {
-      this->defer([obj, action]() {
-        switch (action) {
-          case TOGGLE:
-            obj->toggle();
-            break;
-          case TURN_ON:
-            obj->turn_on();
-            break;
-          case TURN_OFF:
-            obj->turn_off();
-            break;
-          default:
-            break;
-        }
-      });
+    if (action != SWITCH_ACTION_NONE) {
+#ifdef USE_ESP8266
+      execute_switch_action(obj, action);
+#else
+      this->defer([obj, action]() { execute_switch_action(obj, action); });
+#endif
       request->send(200);
     } else {
       request->send(404);
@@ -743,7 +753,7 @@ void WebServer::handle_button_request(AsyncWebServerRequest *request, const UrlM
       std::string data = this->button_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
     } else if (match.method_equals(ESPHOME_F("press"))) {
-      this->defer([obj]() { obj->press(); });
+      DEFER_ACTION(obj, obj->press());
       request->send(200);
       return;
     } else {
@@ -828,7 +838,7 @@ void WebServer::handle_fan_request(AsyncWebServerRequest *request, const UrlMatc
       std::string data = this->fan_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
     } else if (match.method_equals(ESPHOME_F("toggle"))) {
-      this->defer([obj]() { obj->toggle().perform(); });
+      DEFER_ACTION(obj, obj->toggle().perform());
       request->send(200);
     } else {
       bool is_on = match.method_equals(ESPHOME_F("turn_on"));
@@ -859,7 +869,7 @@ void WebServer::handle_fan_request(AsyncWebServerRequest *request, const UrlMatc
             return;
         }
       }
-      this->defer([call]() mutable { call.perform(); });
+      DEFER_ACTION(call, call.perform());
       request->send(200);
     }
     return;
@@ -909,7 +919,7 @@ void WebServer::handle_light_request(AsyncWebServerRequest *request, const UrlMa
       std::string data = this->light_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
     } else if (match.method_equals(ESPHOME_F("toggle"))) {
-      this->defer([obj]() { obj->toggle().perform(); });
+      DEFER_ACTION(obj, obj->toggle().perform());
       request->send(200);
     } else {
       bool is_on = match.method_equals(ESPHOME_F("turn_on"));
@@ -938,7 +948,7 @@ void WebServer::handle_light_request(AsyncWebServerRequest *request, const UrlMa
         parse_string_param_(request, ESPHOME_F("effect"), call, &decltype(call)::set_effect);
       }
 
-      this->defer([call]() mutable { call.perform(); });
+      DEFER_ACTION(call, call.perform());
       request->send(200);
     }
     return;
@@ -1027,7 +1037,7 @@ void WebServer::handle_cover_request(AsyncWebServerRequest *request, const UrlMa
     parse_float_param_(request, ESPHOME_F("position"), call, &decltype(call)::set_position);
     parse_float_param_(request, ESPHOME_F("tilt"), call, &decltype(call)::set_tilt);
 
-    this->defer([call]() mutable { call.perform(); });
+    DEFER_ACTION(call, call.perform());
     request->send(200);
     return;
   }
@@ -1086,7 +1096,7 @@ void WebServer::handle_number_request(AsyncWebServerRequest *request, const UrlM
     auto call = obj->make_call();
     parse_float_param_(request, ESPHOME_F("value"), call, &decltype(call)::set_value);
 
-    this->defer([call]() mutable { call.perform(); });
+    DEFER_ACTION(call, call.perform());
     request->send(200);
     return;
   }
@@ -1159,7 +1169,7 @@ void WebServer::handle_date_request(AsyncWebServerRequest *request, const UrlMat
 
     parse_string_param_(request, ESPHOME_F("value"), call, &decltype(call)::set_date);
 
-    this->defer([call]() mutable { call.perform(); });
+    DEFER_ACTION(call, call.perform());
     request->send(200);
     return;
   }
@@ -1178,11 +1188,7 @@ std::string WebServer::date_json_(datetime::DateEntity *obj, JsonDetail start_co
 
   // Format: YYYY-MM-DD (max 10 chars + null)
   char value[12];
-#ifdef USE_ESP8266
-  snprintf_P(value, sizeof(value), PSTR("%d-%02d-%02d"), obj->year, obj->month, obj->day);
-#else
-  snprintf(value, sizeof(value), "%d-%02d-%02d", obj->year, obj->month, obj->day);
-#endif
+  buf_append_printf(value, sizeof(value), 0, "%d-%02d-%02d", obj->year, obj->month, obj->day);
   set_json_icon_state_value(root, obj, "date", value, value, start_config);
   if (start_config == DETAIL_ALL) {
     this->add_sorting_info_(root, obj);
@@ -1223,7 +1229,7 @@ void WebServer::handle_time_request(AsyncWebServerRequest *request, const UrlMat
 
     parse_string_param_(request, ESPHOME_F("value"), call, &decltype(call)::set_time);
 
-    this->defer([call]() mutable { call.perform(); });
+    DEFER_ACTION(call, call.perform());
     request->send(200);
     return;
   }
@@ -1241,11 +1247,7 @@ std::string WebServer::time_json_(datetime::TimeEntity *obj, JsonDetail start_co
 
   // Format: HH:MM:SS (8 chars + null)
   char value[12];
-#ifdef USE_ESP8266
-  snprintf_P(value, sizeof(value), PSTR("%02d:%02d:%02d"), obj->hour, obj->minute, obj->second);
-#else
-  snprintf(value, sizeof(value), "%02d:%02d:%02d", obj->hour, obj->minute, obj->second);
-#endif
+  buf_append_printf(value, sizeof(value), 0, "%02d:%02d:%02d", obj->hour, obj->minute, obj->second);
   set_json_icon_state_value(root, obj, "time", value, value, start_config);
   if (start_config == DETAIL_ALL) {
     this->add_sorting_info_(root, obj);
@@ -1286,7 +1288,7 @@ void WebServer::handle_datetime_request(AsyncWebServerRequest *request, const Ur
 
     parse_string_param_(request, ESPHOME_F("value"), call, &decltype(call)::set_datetime);
 
-    this->defer([call]() mutable { call.perform(); });
+    DEFER_ACTION(call, call.perform());
     request->send(200);
     return;
   }
@@ -1304,13 +1306,8 @@ std::string WebServer::datetime_json_(datetime::DateTimeEntity *obj, JsonDetail
 
   // Format: YYYY-MM-DD HH:MM:SS (max 19 chars + null)
   char value[24];
-#ifdef USE_ESP8266
-  snprintf_P(value, sizeof(value), PSTR("%d-%02d-%02d %02d:%02d:%02d"), obj->year, obj->month, obj->day, obj->hour,
-             obj->minute, obj->second);
-#else
-  snprintf(value, sizeof(value), "%d-%02d-%02d %02d:%02d:%02d", obj->year, obj->month, obj->day, obj->hour, obj->minute,
-           obj->second);
-#endif
+  buf_append_printf(value, sizeof(value), 0, "%d-%02d-%02d %02d:%02d:%02d", obj->year, obj->month, obj->day, obj->hour,
+                    obj->minute, obj->second);
   set_json_icon_state_value(root, obj, "datetime", value, value, start_config);
   if (start_config == DETAIL_ALL) {
     this->add_sorting_info_(root, obj);
@@ -1346,7 +1343,7 @@ void WebServer::handle_text_request(AsyncWebServerRequest *request, const UrlMat
     auto call = obj->make_call();
     parse_string_param_(request, ESPHOME_F("value"), call, &decltype(call)::set_value);
 
-    this->defer([call]() mutable { call.perform(); });
+    DEFER_ACTION(call, call.perform());
     request->send(200);
     return;
   }
@@ -1404,7 +1401,7 @@ void WebServer::handle_select_request(AsyncWebServerRequest *request, const UrlM
     auto call = obj->make_call();
     parse_string_param_(request, ESPHOME_F("option"), call, &decltype(call)::set_option);
 
-    this->defer([call]() mutable { call.perform(); });
+    DEFER_ACTION(call, call.perform());
     request->send(200);
     return;
   }
@@ -1473,7 +1470,7 @@ void WebServer::handle_climate_request(AsyncWebServerRequest *request, const Url
     parse_float_param_(request, ESPHOME_F("target_temperature_low"), call, &decltype(call)::set_target_temperature_low);
     parse_float_param_(request, ESPHOME_F("target_temperature"), call, &decltype(call)::set_target_temperature);
 
-    this->defer([call]() mutable { call.perform(); });
+    DEFER_ACTION(call, call.perform());
     request->send(200);
     return;
   }
@@ -1589,6 +1586,24 @@ std::string WebServer::climate_json_(climate::Climate *obj, JsonDetail start_con
 #endif
 
 #ifdef USE_LOCK
+enum LockAction : uint8_t { LOCK_ACTION_NONE, LOCK_ACTION_LOCK, LOCK_ACTION_UNLOCK, LOCK_ACTION_OPEN };
+
+static void execute_lock_action(lock::Lock *obj, LockAction action) {
+  switch (action) {
+    case LOCK_ACTION_LOCK:
+      obj->lock();
+      break;
+    case LOCK_ACTION_UNLOCK:
+      obj->unlock();
+      break;
+    case LOCK_ACTION_OPEN:
+      obj->open();
+      break;
+    default:
+      break;
+  }
+}
+
 void WebServer::on_lock_update(lock::Lock *obj) {
   if (!this->include_internal_ && obj->is_internal())
     return;
@@ -1607,34 +1622,22 @@ void WebServer::handle_lock_request(AsyncWebServerRequest *request, const UrlMat
       return;
     }
 
-    // Handle action methods with single defer and response
-    enum LockAction { NONE, LOCK, UNLOCK, OPEN };
-    LockAction action = NONE;
+    LockAction action = LOCK_ACTION_NONE;
 
     if (match.method_equals(ESPHOME_F("lock"))) {
-      action = LOCK;
+      action = LOCK_ACTION_LOCK;
     } else if (match.method_equals(ESPHOME_F("unlock"))) {
-      action = UNLOCK;
+      action = LOCK_ACTION_UNLOCK;
     } else if (match.method_equals(ESPHOME_F("open"))) {
-      action = OPEN;
+      action = LOCK_ACTION_OPEN;
     }
 
-    if (action != NONE) {
-      this->defer([obj, action]() {
-        switch (action) {
-          case LOCK:
-            obj->lock();
-            break;
-          case UNLOCK:
-            obj->unlock();
-            break;
-          case OPEN:
-            obj->open();
-            break;
-          default:
-            break;
-        }
-      });
+    if (action != LOCK_ACTION_NONE) {
+#ifdef USE_ESP8266
+      execute_lock_action(obj, action);
+#else
+      this->defer([obj, action]() { execute_lock_action(obj, action); });
+#endif
       request->send(200);
     } else {
       request->send(404);
@@ -1717,7 +1720,7 @@ void WebServer::handle_valve_request(AsyncWebServerRequest *request, const UrlMa
 
     parse_float_param_(request, ESPHOME_F("position"), call, &decltype(call)::set_position);
 
-    this->defer([call]() mutable { call.perform(); });
+    DEFER_ACTION(call, call.perform());
     request->send(200);
     return;
   }
@@ -1796,7 +1799,7 @@ void WebServer::handle_alarm_control_panel_request(AsyncWebServerRequest *reques
       return;
     }
 
-    this->defer([call]() mutable { call.perform(); });
+    DEFER_ACTION(call, call.perform());
     request->send(200);
     return;
   }
@@ -1872,7 +1875,7 @@ void WebServer::handle_water_heater_request(AsyncWebServerRequest *request, cons
     // Parse on/off parameter
     parse_bool_param_(request, ESPHOME_F("is_on"), base_call, &water_heater::WaterHeaterCall::set_on);
 
-    this->defer([call]() mutable { call.perform(); });
+    DEFER_ACTION(call, call.perform());
     request->send(200);
     return;
   }
@@ -1940,6 +1943,110 @@ std::string WebServer::water_heater_json_(water_heater::WaterHeater *obj, JsonDe
 }
 #endif
 
+#ifdef USE_INFRARED
+void WebServer::handle_infrared_request(AsyncWebServerRequest *request, const UrlMatch &match) {
+  for (infrared::Infrared *obj : App.get_infrareds()) {
+    auto entity_match = match.match_entity(obj);
+    if (!entity_match.matched)
+      continue;
+
+    if (request->method() == HTTP_GET && entity_match.action_is_empty) {
+      auto detail = get_request_detail(request);
+      std::string data = this->infrared_json_(obj, detail);
+      request->send(200, ESPHOME_F("application/json"), data.c_str());
+      return;
+    }
+    if (!match.method_equals(ESPHOME_F("transmit"))) {
+      request->send(404);
+      return;
+    }
+
+    // Only allow transmit if the device supports it
+    if (!obj->has_transmitter()) {
+      request->send(400, ESPHOME_F("text/plain"), "Device does not support transmission");
+      return;
+    }
+
+    // Parse parameters
+    auto call = obj->make_call();
+
+    // Parse carrier frequency (optional)
+    if (request->hasParam(ESPHOME_F("carrier_frequency"))) {
+      auto value = parse_number<uint32_t>(request->getParam(ESPHOME_F("carrier_frequency"))->value().c_str());
+      if (value.has_value()) {
+        call.set_carrier_frequency(*value);
+      }
+    }
+
+    // Parse repeat count (optional, defaults to 1)
+    if (request->hasParam(ESPHOME_F("repeat_count"))) {
+      auto value = parse_number<uint32_t>(request->getParam(ESPHOME_F("repeat_count"))->value().c_str());
+      if (value.has_value()) {
+        call.set_repeat_count(*value);
+      }
+    }
+
+    // Parse base64url-encoded raw timings (required)
+    // Base64url is URL-safe: uses A-Za-z0-9-_ (no special characters needing escaping)
+    if (!request->hasParam(ESPHOME_F("data"))) {
+      request->send(400, ESPHOME_F("text/plain"), "Missing 'data' parameter");
+      return;
+    }
+
+    // .c_str() is required for Arduino framework where value() returns Arduino String instead of std::string
+    std::string encoded =
+        request->getParam(ESPHOME_F("data"))->value().c_str();  // NOLINT(readability-redundant-string-cstr)
+
+    // Validate base64url is not empty
+    if (encoded.empty()) {
+      request->send(400, ESPHOME_F("text/plain"), "Empty 'data' parameter");
+      return;
+    }
+
+#ifdef USE_ESP8266
+    // ESP8266 is single-threaded, call directly
+    call.set_raw_timings_base64url(encoded);
+    call.perform();
+#else
+    // Defer to main loop for thread safety. Move encoded string into lambda to ensure
+    // it outlives the call - set_raw_timings_base64url stores a pointer, so the string
+    // must remain valid until perform() completes.
+    this->defer([call, encoded = std::move(encoded)]() mutable {
+      call.set_raw_timings_base64url(encoded);
+      call.perform();
+    });
+#endif
+
+    request->send(200);
+    return;
+  }
+  request->send(404);
+}
+
+std::string WebServer::infrared_all_json_generator(WebServer *web_server, void *source) {
+  // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
+  return web_server->infrared_json_(static_cast<infrared::Infrared *>(source), DETAIL_ALL);
+}
+
+std::string WebServer::infrared_json_(infrared::Infrared *obj, JsonDetail start_config) {
+  json::JsonBuilder builder;
+  JsonObject root = builder.root();
+
+  set_json_icon_state_value(root, obj, "infrared", "", 0, start_config);
+
+  auto traits = obj->get_traits();
+
+  root[ESPHOME_F("supports_transmitter")] = traits.get_supports_transmitter();
+  root[ESPHOME_F("supports_receiver")] = traits.get_supports_receiver();
+
+  if (start_config == DETAIL_ALL) {
+    this->add_sorting_info_(root, obj);
+  }
+
+  return builder.serialize();
+}
+#endif
+
 #ifdef USE_EVENT
 void WebServer::on_event(event::Event *obj) {
   if (!this->include_internal_ && obj->is_internal())
@@ -2032,7 +2139,7 @@ void WebServer::handle_update_request(AsyncWebServerRequest *request, const UrlM
       return;
     }
 
-    this->defer([obj]() mutable { obj->perform(); });
+    DEFER_ACTION(obj, obj->perform());
     request->send(200);
     return;
   }
@@ -2071,24 +2178,21 @@ bool WebServer::canHandle(AsyncWebServerRequest *request) const {
   const auto &url = request->url();
   const auto method = request->method();
 
-  // Static URL checks
-  static const char *const STATIC_URLS[] = {
-    "/",
+  // Static URL checks - use ESPHOME_F to keep strings in flash on ESP8266
+  if (url == ESPHOME_F("/"))
+    return true;
 #if !defined(USE_ESP32) && defined(USE_ARDUINO)
-    "/events",
+  if (url == ESPHOME_F("/events"))
+    return true;
 #endif
 #ifdef USE_WEBSERVER_CSS_INCLUDE
-    "/0.css",
+  if (url == ESPHOME_F("/0.css"))
+    return true;
 #endif
 #ifdef USE_WEBSERVER_JS_INCLUDE
-    "/0.js",
+  if (url == ESPHOME_F("/0.js"))
+    return true;
 #endif
-  };
-
-  for (const auto &static_url : STATIC_URLS) {
-    if (url == static_url)
-      return true;
-  }
 
 #ifdef USE_WEBSERVER_PRIVATE_NETWORK_ACCESS
   if (method == HTTP_OPTIONS && request->hasHeader(ESPHOME_F("Access-Control-Request-Private-Network")))
@@ -2108,90 +2212,100 @@ bool WebServer::canHandle(AsyncWebServerRequest *request) const {
   if (!is_get_or_post)
     return false;
 
-  // Use lookup tables for domain checks
-  static const char *const GET_ONLY_DOMAINS[] = {
+  // Check GET-only domains - use ESPHOME_F to keep strings in flash on ESP8266
+  if (is_get) {
 #ifdef USE_SENSOR
-      "sensor",
+    if (match.domain_equals(ESPHOME_F("sensor")))
+      return true;
 #endif
 #ifdef USE_BINARY_SENSOR
-      "binary_sensor",
+    if (match.domain_equals(ESPHOME_F("binary_sensor")))
+      return true;
 #endif
 #ifdef USE_TEXT_SENSOR
-      "text_sensor",
+    if (match.domain_equals(ESPHOME_F("text_sensor")))
+      return true;
 #endif
 #ifdef USE_EVENT
-      "event",
+    if (match.domain_equals(ESPHOME_F("event")))
+      return true;
 #endif
-  };
-
-  static const char *const GET_POST_DOMAINS[] = {
-#ifdef USE_SWITCH
-      "switch",
-#endif
-#ifdef USE_BUTTON
-      "button",
-#endif
-#ifdef USE_FAN
-      "fan",
-#endif
-#ifdef USE_LIGHT
-      "light",
-#endif
-#ifdef USE_COVER
-      "cover",
-#endif
-#ifdef USE_NUMBER
-      "number",
-#endif
-#ifdef USE_DATETIME_DATE
-      "date",
-#endif
-#ifdef USE_DATETIME_TIME
-      "time",
-#endif
-#ifdef USE_DATETIME_DATETIME
-      "datetime",
-#endif
-#ifdef USE_TEXT
-      "text",
-#endif
-#ifdef USE_SELECT
-      "select",
-#endif
-#ifdef USE_CLIMATE
-      "climate",
-#endif
-#ifdef USE_LOCK
-      "lock",
-#endif
-#ifdef USE_VALVE
-      "valve",
-#endif
-#ifdef USE_ALARM_CONTROL_PANEL
-      "alarm_control_panel",
-#endif
-#ifdef USE_UPDATE
-      "update",
-#endif
-#ifdef USE_WATER_HEATER
-      "water_heater",
-#endif
-  };
-
-  // Check GET-only domains
-  if (is_get) {
-    for (const auto &domain : GET_ONLY_DOMAINS) {
-      if (match.domain_equals(domain))
-        return true;
-    }
   }
 
   // Check GET+POST domains
   if (is_get_or_post) {
-    for (const auto &domain : GET_POST_DOMAINS) {
-      if (match.domain_equals(domain))
-        return true;
-    }
+#ifdef USE_SWITCH
+    if (match.domain_equals(ESPHOME_F("switch")))
+      return true;
+#endif
+#ifdef USE_BUTTON
+    if (match.domain_equals(ESPHOME_F("button")))
+      return true;
+#endif
+#ifdef USE_FAN
+    if (match.domain_equals(ESPHOME_F("fan")))
+      return true;
+#endif
+#ifdef USE_LIGHT
+    if (match.domain_equals(ESPHOME_F("light")))
+      return true;
+#endif
+#ifdef USE_COVER
+    if (match.domain_equals(ESPHOME_F("cover")))
+      return true;
+#endif
+#ifdef USE_NUMBER
+    if (match.domain_equals(ESPHOME_F("number")))
+      return true;
+#endif
+#ifdef USE_DATETIME_DATE
+    if (match.domain_equals(ESPHOME_F("date")))
+      return true;
+#endif
+#ifdef USE_DATETIME_TIME
+    if (match.domain_equals(ESPHOME_F("time")))
+      return true;
+#endif
+#ifdef USE_DATETIME_DATETIME
+    if (match.domain_equals(ESPHOME_F("datetime")))
+      return true;
+#endif
+#ifdef USE_TEXT
+    if (match.domain_equals(ESPHOME_F("text")))
+      return true;
+#endif
+#ifdef USE_SELECT
+    if (match.domain_equals(ESPHOME_F("select")))
+      return true;
+#endif
+#ifdef USE_CLIMATE
+    if (match.domain_equals(ESPHOME_F("climate")))
+      return true;
+#endif
+#ifdef USE_LOCK
+    if (match.domain_equals(ESPHOME_F("lock")))
+      return true;
+#endif
+#ifdef USE_VALVE
+    if (match.domain_equals(ESPHOME_F("valve")))
+      return true;
+#endif
+#ifdef USE_ALARM_CONTROL_PANEL
+    if (match.domain_equals(ESPHOME_F("alarm_control_panel")))
+      return true;
+#endif
+#ifdef USE_UPDATE
+    if (match.domain_equals(ESPHOME_F("update")))
+      return true;
+#endif
+#ifdef USE_WATER_HEATER
+    if (match.domain_equals(ESPHOME_F("water_heater")))
+      return true;
+#endif
+#ifdef USE_INFRARED
+    if (match.domain_equals(ESPHOME_F("infrared")))
+      return true;
+#endif
   }
 
   return false;
@@ -2340,6 +2454,11 @@ void WebServer::handleRequest(AsyncWebServerRequest *request) {
   else if (match.domain_equals(ESPHOME_F("water_heater"))) {
     this->handle_water_heater_request(request, match);
   }
+#endif
+#ifdef USE_INFRARED
+  else if (match.domain_equals(ESPHOME_F("infrared"))) {
+    this->handle_infrared_request(request, match);
+  }
 #endif
   else {
     // No matching handler found - send 404
diff --git a/esphome/components/web_server/web_server.h b/esphome/components/web_server/web_server.h
index b1a495ebef..92a5c7edee 100644
--- a/esphome/components/web_server/web_server.h
+++ b/esphome/components/web_server/web_server.h
@@ -42,6 +42,14 @@ using ParamNameType = const __FlashStringHelper *;
 using ParamNameType = const char *;
 #endif
 
+// ESP8266 is single-threaded, so actions can execute directly in request context.
+// Multi-core platforms need to defer to main loop thread for thread safety.
+#ifdef USE_ESP8266
+#define DEFER_ACTION(capture, action) action
+#else
+#define DEFER_ACTION(capture, action) this->defer([capture]() mutable { action; })
+#endif
+
 /// Result of matching a URL against an entity
 struct EntityMatchResult {
   bool matched;          ///< True if entity matched the URL
@@ -452,6 +460,13 @@ class WebServer : public Controller,
   static std::string water_heater_all_json_generator(WebServer *web_server, void *source);
 #endif
 
+#ifdef USE_INFRARED
+  /// Handle an infrared request under '/infrared/<id>/transmit'.
+  void handle_infrared_request(AsyncWebServerRequest *request, const UrlMatch &match);
+
+  static std::string infrared_all_json_generator(WebServer *web_server, void *source);
+#endif
+
 #ifdef USE_EVENT
   void on_event(event::Event *obj) override;
 
@@ -654,6 +669,9 @@ class WebServer : public Controller,
 #ifdef USE_WATER_HEATER
   std::string water_heater_json_(water_heater::WaterHeater *obj, JsonDetail start_config);
 #endif
+#ifdef USE_INFRARED
+  std::string infrared_json_(infrared::Infrared *obj, JsonDetail start_config);
+#endif
 #ifdef USE_UPDATE
   std::string update_json_(update::UpdateEntity *obj, JsonDetail start_config);
 #endif
diff --git a/esphome/components/web_server_idf/web_server_idf.cpp b/esphome/components/web_server_idf/web_server_idf.cpp
index 55d2040a3a..abeda5fc46 100644
--- a/esphome/components/web_server_idf/web_server_idf.cpp
+++ b/esphome/components/web_server_idf/web_server_idf.cpp
@@ -487,7 +487,7 @@ void AsyncEventSource::deferrable_send_state(void *source, const char *event_typ
 AsyncEventSourceResponse::AsyncEventSourceResponse(const AsyncWebServerRequest *request,
                                                    esphome::web_server_idf::AsyncEventSource *server,
                                                    esphome::web_server::WebServer *ws)
-    : server_(server), web_server_(ws), entities_iterator_(new esphome::web_server::ListEntitiesIterator(ws, server)) {
+    : server_(server), web_server_(ws), entities_iterator_(ws, server) {
   httpd_req_t *req = *request;
 
   httpd_resp_set_status(req, HTTPD_200);
@@ -531,12 +531,12 @@ AsyncEventSourceResponse::AsyncEventSourceResponse(const AsyncWebServerRequest *
   }
 #endif
 
-  this->entities_iterator_->begin(ws->include_internal_);
+  this->entities_iterator_.begin(ws->include_internal_);
 
   // just dump them all up-front and take advantage of the deferred queue
   //     on second thought that takes too long, but leaving the commented code here for debug purposes
-  // while(!this->entities_iterator_->completed()) {
-  //  this->entities_iterator_->advance();
+  // while(!this->entities_iterator_.completed()) {
+  //  this->entities_iterator_.advance();
   //}
 }
 
@@ -634,8 +634,8 @@ void AsyncEventSourceResponse::process_buffer_() {
 void AsyncEventSourceResponse::loop() {
   process_buffer_();
   process_deferred_queue_();
-  if (!this->entities_iterator_->completed())
-    this->entities_iterator_->advance();
+  if (!this->entities_iterator_.completed())
+    this->entities_iterator_.advance();
 }
 
 bool AsyncEventSourceResponse::try_send_nodefer(const char *message, const char *event, uint32_t id,
@@ -781,7 +781,7 @@ void AsyncEventSourceResponse::deferrable_send_state(void *source, const char *e
                                                      message_generator_t *message_generator) {
   // allow all json "details_all" to go through before publishing bare state events, this avoids unnamed entries showing
   // up in the web GUI and reduces event load during initial connect
-  if (!entities_iterator_->completed() && 0 != strcmp(event_type, "state_detail_all"))
+  if (!this->entities_iterator_.completed() && 0 != strcmp(event_type, "state_detail_all"))
     return;
 
   if (source == nullptr)
diff --git a/esphome/components/web_server_idf/web_server_idf.h b/esphome/components/web_server_idf/web_server_idf.h
index 2a334a11e3..a6c984792a 100644
--- a/esphome/components/web_server_idf/web_server_idf.h
+++ b/esphome/components/web_server_idf/web_server_idf.h
@@ -13,11 +13,14 @@
 #include <utility>
 #include <vector>
 
+#ifdef USE_WEBSERVER
+#include "esphome/components/web_server/list_entities.h"
+#endif
+
 namespace esphome {
 #ifdef USE_WEBSERVER
 namespace web_server {
 class WebServer;
-class ListEntitiesIterator;
 };  // namespace web_server
 #endif
 namespace web_server_idf {
@@ -284,7 +287,7 @@ class AsyncEventSourceResponse {
   std::atomic<int> fd_{};
   std::vector<DeferredEvent> deferred_queue_;
   esphome::web_server::WebServer *web_server_;
-  std::unique_ptr<esphome::web_server::ListEntitiesIterator> entities_iterator_;
+  esphome::web_server::ListEntitiesIterator entities_iterator_;
   std::string event_buffer_{""};
   size_t event_bytes_sent_;
   uint16_t consecutive_send_failures_{0};
diff --git a/esphome/components/weikai/weikai.cpp b/esphome/components/weikai/weikai.cpp
index 3384a0572f..d0a8f8366b 100644
--- a/esphome/components/weikai/weikai.cpp
+++ b/esphome/components/weikai/weikai.cpp
@@ -4,19 +4,13 @@
 /// @details The classes declared in this file can be used by the Weikai family
 
 #include "weikai.h"
+#include "esphome/core/helpers.h"
 
 namespace esphome {
 namespace weikai {
 
 static const char *const TAG = "weikai";
 
-/// @brief convert an int to binary representation as C++ std::string
-/// @param val integer to convert
-/// @return a std::string
-inline std::string i2s(uint8_t val) { return std::bitset<8>(val).to_string(); }
-/// Convert std::string to C string
-#define I2S2CS(val) (i2s(val).c_str())
-
 /// @brief measure the time elapsed between two calls
 /// @param last_time time of the previous call
 /// @return the elapsed time in milliseconds
@@ -170,17 +164,18 @@ void WeikaiComponent::test_gpio_input_() {
   static bool init_input{false};
   static uint8_t state{0};
   uint8_t value;
+  char bin_buf[9];  // 8 binary digits + null
   if (!init_input) {
     init_input = true;
     // set all pins in input mode
     this->reg(WKREG_GPDIR, 0) = 0x00;
     ESP_LOGI(TAG, "initializing all pins to input mode");
     state = this->reg(WKREG_GPDAT, 0);
-    ESP_LOGI(TAG, "initial input data state = %02X (%s)", state, I2S2CS(state));
+    ESP_LOGI(TAG, "initial input data state = %02X (%s)", state, format_bin_to(bin_buf, state));
   }
   value = this->reg(WKREG_GPDAT, 0);
   if (value != state) {
-    ESP_LOGI(TAG, "Input data changed from %02X to %02X (%s)", state, value, I2S2CS(value));
+    ESP_LOGI(TAG, "Input data changed from %02X to %02X (%s)", state, value, format_bin_to(bin_buf, value));
     state = value;
   }
 }
@@ -188,6 +183,7 @@ void WeikaiComponent::test_gpio_input_() {
 void WeikaiComponent::test_gpio_output_() {
   static bool init_output{false};
   static uint8_t state{0};
+  char bin_buf[9];  // 8 binary digits + null
   if (!init_output) {
     init_output = true;
     // set all pins in output mode
@@ -198,7 +194,7 @@ void WeikaiComponent::test_gpio_output_() {
   }
   state = ~state;
   this->reg(WKREG_GPDAT, 0) = state;
-  ESP_LOGI(TAG, "Flipping all outputs to %02X (%s)", state, I2S2CS(state));
+  ESP_LOGI(TAG, "Flipping all outputs to %02X (%s)", state, format_bin_to(bin_buf, state));
   delay(100);  // NOLINT
 }
 #endif
@@ -208,7 +204,9 @@ void WeikaiComponent::test_gpio_output_() {
 ///////////////////////////////////////////////////////////////////////////////
 bool WeikaiComponent::read_pin_val_(uint8_t pin) {
   this->input_state_ = this->reg(WKREG_GPDAT, 0);
-  ESP_LOGVV(TAG, "reading input pin %u = %u in_state %s", pin, this->input_state_ & (1 << pin), I2S2CS(input_state_));
+  char bin_buf[9];
+  ESP_LOGVV(TAG, "reading input pin %u = %u in_state %s", pin, this->input_state_ & (1 << pin),
+            format_bin_to(bin_buf, this->input_state_));
   return this->input_state_ & (1 << pin);
 }
 
@@ -218,7 +216,9 @@ void WeikaiComponent::write_pin_val_(uint8_t pin, bool value) {
   } else {
     this->output_state_ &= ~(1 << pin);
   }
-  ESP_LOGVV(TAG, "writing output pin %d with %d out_state %s", pin, uint8_t(value), I2S2CS(this->output_state_));
+  char bin_buf[9];
+  ESP_LOGVV(TAG, "writing output pin %d with %d out_state %s", pin, uint8_t(value),
+            format_bin_to(bin_buf, this->output_state_));
   this->reg(WKREG_GPDAT, 0) = this->output_state_;
 }
 
@@ -232,7 +232,8 @@ void WeikaiComponent::set_pin_direction_(uint8_t pin, gpio::Flags flags) {
       ESP_LOGE(TAG, "pin %d direction invalid", pin);
     }
   }
-  ESP_LOGVV(TAG, "setting pin %d direction to %d pin_config=%s", pin, flags, I2S2CS(this->pin_config_));
+  char bin_buf[9];
+  ESP_LOGVV(TAG, "setting pin %d direction to %d pin_config=%s", pin, flags, format_bin_to(bin_buf, this->pin_config_));
   this->reg(WKREG_GPDIR, 0) = this->pin_config_;  // TODO check ~
 }
 
@@ -241,12 +242,11 @@ void WeikaiGPIOPin::setup() {
                 flags_ == gpio::FLAG_INPUT          ? "Input"
                 : this->flags_ == gpio::FLAG_OUTPUT ? "Output"
                                                     : "NOT SPECIFIED");
-  // ESP_LOGCONFIG(TAG, "Setting GPIO pins mode to '%s' %02X", I2S2CS(this->flags_), this->flags_);
   this->pin_mode(this->flags_);
 }
 
 size_t WeikaiGPIOPin::dump_summary(char *buffer, size_t len) const {
-  return snprintf(buffer, len, "%u via WeiKai %s", this->pin_, this->parent_->get_name());
+  return buf_append_printf(buffer, len, 0, "%u via WeiKai %s", this->pin_, this->parent_->get_name());
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -297,8 +297,9 @@ void WeikaiChannel::set_line_param_() {
       break;  // no parity 000x
   }
   this->reg(WKREG_LCR) = lcr;  // write LCR
+  char bin_buf[9];
   ESP_LOGV(TAG, "    line config: %d data_bits, %d stop_bits, parity %s register [%s]", this->data_bits_,
-           this->stop_bits_, p2s(this->parity_), I2S2CS(lcr));
+           this->stop_bits_, p2s(this->parity_), format_bin_to(bin_buf, lcr));
 }
 
 void WeikaiChannel::set_baudrate_() {
@@ -334,7 +335,8 @@ size_t WeikaiChannel::tx_in_fifo_() {
   if (tfcnt == 0) {
     uint8_t const fsr = this->reg(WKREG_FSR);
     if (fsr & FSR_TFFULL) {
-      ESP_LOGVV(TAG, "tx FIFO full FSR=%s", I2S2CS(fsr));
+      char bin_buf[9];
+      ESP_LOGVV(TAG, "tx FIFO full FSR=%s", format_bin_to(bin_buf, fsr));
       tfcnt = FIFO_SIZE;
     }
   }
@@ -346,14 +348,15 @@ size_t WeikaiChannel::rx_in_fifo_() {
   size_t available = this->reg(WKREG_RFCNT);
   uint8_t const fsr = this->reg(WKREG_FSR);
   if (fsr & (FSR_RFOE | FSR_RFLB | FSR_RFFE | FSR_RFPE)) {
+    char bin_buf[9];
     if (fsr & FSR_RFOE)
-      ESP_LOGE(TAG, "Receive data overflow FSR=%s", I2S2CS(fsr));
+      ESP_LOGE(TAG, "Receive data overflow FSR=%s", format_bin_to(bin_buf, fsr));
     if (fsr & FSR_RFLB)
-      ESP_LOGE(TAG, "Receive line break FSR=%s", I2S2CS(fsr));
+      ESP_LOGE(TAG, "Receive line break FSR=%s", format_bin_to(bin_buf, fsr));
     if (fsr & FSR_RFFE)
-      ESP_LOGE(TAG, "Receive frame error FSR=%s", I2S2CS(fsr));
+      ESP_LOGE(TAG, "Receive frame error FSR=%s", format_bin_to(bin_buf, fsr));
     if (fsr & FSR_RFPE)
-      ESP_LOGE(TAG, "Receive parity error FSR=%s", I2S2CS(fsr));
+      ESP_LOGE(TAG, "Receive parity error FSR=%s", format_bin_to(bin_buf, fsr));
   }
   if ((available == 0) && (fsr & FSR_RFDAT)) {
     // here we should be very careful because we can have something like this:
@@ -362,11 +365,13 @@ size_t WeikaiChannel::rx_in_fifo_() {
     // -  so to be sure we need to do another read of RFCNT and if it is still zero -> buffer full
     available = this->reg(WKREG_RFCNT);
     if (available == 0) {  // still zero ?
-      ESP_LOGV(TAG, "rx FIFO is full FSR=%s", I2S2CS(fsr));
+      char bin_buf[9];
+      ESP_LOGV(TAG, "rx FIFO is full FSR=%s", format_bin_to(bin_buf, fsr));
       available = FIFO_SIZE;
     }
   }
-  ESP_LOGVV(TAG, "rx FIFO contain %d bytes - FSR status=%s", available, I2S2CS(fsr));
+  char bin_buf2[9];
+  ESP_LOGVV(TAG, "rx FIFO contain %d bytes - FSR status=%s", available, format_bin_to(bin_buf2, fsr));
   return available;
 }
 
diff --git a/esphome/components/weikai/weikai.h b/esphome/components/weikai/weikai.h
index a27c14106d..4440d9414e 100644
--- a/esphome/components/weikai/weikai.h
+++ b/esphome/components/weikai/weikai.h
@@ -8,7 +8,6 @@
 ///                 wk2132_i2c, wk2168_i2c, wk2204_i2c, wk2212_i2c
 
 #pragma once
-#include <bitset>
 #include <memory>
 #include <cinttypes>
 #include "esphome/core/component.h"
diff --git a/esphome/components/weikai_spi/weikai_spi.cpp b/esphome/components/weikai_spi/weikai_spi.cpp
index 7bcb817f09..20671a5815 100644
--- a/esphome/components/weikai_spi/weikai_spi.cpp
+++ b/esphome/components/weikai_spi/weikai_spi.cpp
@@ -10,13 +10,6 @@ namespace weikai_spi {
 using namespace weikai;
 static const char *const TAG = "weikai_spi";
 
-/// @brief convert an int to binary representation as C++ std::string
-/// @param val integer to convert
-/// @return a std::string
-inline std::string i2s(uint8_t val) { return std::bitset<8>(val).to_string(); }
-/// Convert std::string to C string
-#define I2S2CS(val) (i2s(val).c_str())
-
 /// @brief measure the time elapsed between two calls
 /// @param last_time time of the previous call
 /// @return the elapsed time in microseconds
@@ -107,7 +100,8 @@ uint8_t WeikaiRegisterSPI::read_reg() const {
   spi_comp->write_byte(cmd);
   uint8_t val = spi_comp->read_byte();
   spi_comp->disable();
-  ESP_LOGVV(TAG, "WeikaiRegisterSPI::read_reg() cmd=%s(%02X) reg=%s ch=%d buf=%02X", I2S2CS(cmd), cmd,
+  char bin_buf[9];
+  ESP_LOGVV(TAG, "WeikaiRegisterSPI::read_reg() cmd=%s(%02X) reg=%s ch=%d buf=%02X", format_bin_to(bin_buf, cmd), cmd,
             reg_to_str(this->register_, this->comp_->page1()), this->channel_, val);
   return val;
 }
@@ -120,8 +114,9 @@ void WeikaiRegisterSPI::read_fifo(uint8_t *data, size_t length) const {
   spi_comp->read_array(data, length);
   spi_comp->disable();
 #ifdef ESPHOME_LOG_HAS_VERY_VERBOSE
-  ESP_LOGVV(TAG, "WeikaiRegisterSPI::read_fifo() cmd=%s(%02X) ch=%d len=%d buffer", I2S2CS(cmd), cmd, this->channel_,
-            length);
+  char bin_buf[9];
+  ESP_LOGVV(TAG, "WeikaiRegisterSPI::read_fifo() cmd=%s(%02X) ch=%d len=%d buffer", format_bin_to(bin_buf, cmd), cmd,
+            this->channel_, length);
   print_buffer(data, length);
 #endif
 }
@@ -132,8 +127,9 @@ void WeikaiRegisterSPI::write_reg(uint8_t value) {
   spi_comp->enable();
   spi_comp->write_array(buf, 2);
   spi_comp->disable();
-  ESP_LOGVV(TAG, "WeikaiRegisterSPI::write_reg() cmd=%s(%02X) reg=%s ch=%d buf=%02X", I2S2CS(buf[0]), buf[0],
-            reg_to_str(this->register_, this->comp_->page1()), this->channel_, buf[1]);
+  char bin_buf[9];
+  ESP_LOGVV(TAG, "WeikaiRegisterSPI::write_reg() cmd=%s(%02X) reg=%s ch=%d buf=%02X", format_bin_to(bin_buf, buf[0]),
+            buf[0], reg_to_str(this->register_, this->comp_->page1()), this->channel_, buf[1]);
 }
 
 void WeikaiRegisterSPI::write_fifo(uint8_t *data, size_t length) {
@@ -145,8 +141,9 @@ void WeikaiRegisterSPI::write_fifo(uint8_t *data, size_t length) {
   spi_comp->disable();
 
 #ifdef ESPHOME_LOG_HAS_VERY_VERBOSE
-  ESP_LOGVV(TAG, "WeikaiRegisterSPI::write_fifo() cmd=%s(%02X) ch=%d len=%d buffer", I2S2CS(cmd), cmd, this->channel_,
-            length);
+  char bin_buf[9];
+  ESP_LOGVV(TAG, "WeikaiRegisterSPI::write_fifo() cmd=%s(%02X) ch=%d len=%d buffer", format_bin_to(bin_buf, cmd), cmd,
+            this->channel_, length);
   print_buffer(data, length);
 #endif
 }
diff --git a/esphome/components/weikai_spi/weikai_spi.h b/esphome/components/weikai_spi/weikai_spi.h
index dd0dc8d495..a75b85dc8e 100644
--- a/esphome/components/weikai_spi/weikai_spi.h
+++ b/esphome/components/weikai_spi/weikai_spi.h
@@ -6,7 +6,6 @@
 ///          wk2124_spi, wk2132_spi, wk2168_spi, wk2204_spi, wk2212_spi,
 
 #pragma once
-#include <bitset>
 #include <memory>
 #include "esphome/core/component.h"
 #include "esphome/components/uart/uart.h"
diff --git a/esphome/components/wiegand/wiegand.cpp b/esphome/components/wiegand/wiegand.cpp
index dd1443d10c..f3f578794a 100644
--- a/esphome/components/wiegand/wiegand.cpp
+++ b/esphome/components/wiegand/wiegand.cpp
@@ -1,4 +1,5 @@
 #include "wiegand.h"
+#include <cinttypes>
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
@@ -69,32 +70,35 @@ void Wiegand::loop() {
   for (auto *trigger : this->raw_triggers_)
     trigger->trigger(count, value);
   if (count == 26) {
-    std::string tag = to_string((value >> 1) & 0xffffff);
-    ESP_LOGD(TAG, "received 26-bit tag: %s", tag.c_str());
+    char tag_buf[12];  // max 8 digits for 24-bit value + null
+    buf_append_printf(tag_buf, sizeof(tag_buf), 0, "%" PRIu32, static_cast<uint32_t>((value >> 1) & 0xffffff));
+    ESP_LOGD(TAG, "received 26-bit tag: %s", tag_buf);
     if (!check_eparity(value, 13, 13) || !check_oparity(value, 0, 13)) {
       ESP_LOGW(TAG, "invalid parity");
       return;
     }
     for (auto *trigger : this->tag_triggers_)
-      trigger->trigger(tag);
+      trigger->trigger(tag_buf);
   } else if (count == 34) {
-    std::string tag = to_string((value >> 1) & 0xffffffff);
-    ESP_LOGD(TAG, "received 34-bit tag: %s", tag.c_str());
+    char tag_buf[12];  // max 10 digits for 32-bit value + null
+    buf_append_printf(tag_buf, sizeof(tag_buf), 0, "%" PRIu32, static_cast<uint32_t>((value >> 1) & 0xffffffff));
+    ESP_LOGD(TAG, "received 34-bit tag: %s", tag_buf);
     if (!check_eparity(value, 17, 17) || !check_oparity(value, 0, 17)) {
       ESP_LOGW(TAG, "invalid parity");
       return;
     }
     for (auto *trigger : this->tag_triggers_)
-      trigger->trigger(tag);
+      trigger->trigger(tag_buf);
   } else if (count == 37) {
-    std::string tag = to_string((value >> 1) & 0x7ffffffff);
-    ESP_LOGD(TAG, "received 37-bit tag: %s", tag.c_str());
+    char tag_buf[12];  // max 11 digits for 35-bit value + null
+    buf_append_printf(tag_buf, sizeof(tag_buf), 0, "%" PRIu64, static_cast<uint64_t>((value >> 1) & 0x7ffffffff));
+    ESP_LOGD(TAG, "received 37-bit tag: %s", tag_buf);
     if (!check_eparity(value, 18, 19) || !check_oparity(value, 0, 19)) {
       ESP_LOGW(TAG, "invalid parity");
       return;
     }
     for (auto *trigger : this->tag_triggers_)
-      trigger->trigger(tag);
+      trigger->trigger(tag_buf);
   } else if (count == 4) {
     for (auto *trigger : this->key_triggers_)
       trigger->trigger(value);
diff --git a/esphome/components/wifi/wifi_component_esp8266.cpp b/esphome/components/wifi/wifi_component_esp8266.cpp
index 6fb5dd5769..de0600cf5b 100644
--- a/esphome/components/wifi/wifi_component_esp8266.cpp
+++ b/esphome/components/wifi/wifi_component_esp8266.cpp
@@ -920,7 +920,16 @@ bssid_t WiFiComponent::wifi_bssid() {
   }
   return bssid;
 }
-std::string WiFiComponent::wifi_ssid() { return WiFi.SSID().c_str(); }
+std::string WiFiComponent::wifi_ssid() {
+  struct station_config conf {};
+  if (!wifi_station_get_config(&conf)) {
+    return "";
+  }
+  // conf.ssid is uint8[32], not null-terminated if full
+  auto *ssid_s = reinterpret_cast<const char *>(conf.ssid);
+  size_t len = strnlen(ssid_s, sizeof(conf.ssid));
+  return {ssid_s, len};
+}
 const char *WiFiComponent::wifi_ssid_to(std::span<char, SSID_BUFFER_SIZE> buffer) {
   struct station_config conf {};
   if (!wifi_station_get_config(&conf)) {
@@ -934,16 +943,24 @@ const char *WiFiComponent::wifi_ssid_to(std::span<char, SSID_BUFFER_SIZE> buffer
   return buffer.data();
 }
 int8_t WiFiComponent::wifi_rssi() {
-  if (WiFi.status() != WL_CONNECTED)
+  if (wifi_station_get_connect_status() != STATION_GOT_IP)
     return WIFI_RSSI_DISCONNECTED;
-  int8_t rssi = WiFi.RSSI();
+  sint8 rssi = wifi_station_get_rssi();
   // Values >= 31 are error codes per NONOS SDK API, not valid RSSI readings
   return rssi >= 31 ? WIFI_RSSI_DISCONNECTED : rssi;
 }
-int32_t WiFiComponent::get_wifi_channel() { return WiFi.channel(); }
-network::IPAddress WiFiComponent::wifi_subnet_mask_() { return {(const ip_addr_t *) WiFi.subnetMask()}; }
-network::IPAddress WiFiComponent::wifi_gateway_ip_() { return {(const ip_addr_t *) WiFi.gatewayIP()}; }
-network::IPAddress WiFiComponent::wifi_dns_ip_(int num) { return {(const ip_addr_t *) WiFi.dnsIP(num)}; }
+int32_t WiFiComponent::get_wifi_channel() { return wifi_get_channel(); }
+network::IPAddress WiFiComponent::wifi_subnet_mask_() {
+  struct ip_info ip {};
+  wifi_get_ip_info(STATION_IF, &ip);
+  return network::IPAddress(&ip.netmask);
+}
+network::IPAddress WiFiComponent::wifi_gateway_ip_() {
+  struct ip_info ip {};
+  wifi_get_ip_info(STATION_IF, &ip);
+  return network::IPAddress(&ip.gw);
+}
+network::IPAddress WiFiComponent::wifi_dns_ip_(int num) { return network::IPAddress(dns_getserver(num)); }
 void WiFiComponent::wifi_loop_() {}
 
 }  // namespace esphome::wifi
diff --git a/esphome/components/wifi/wifi_component_esp_idf.cpp b/esphome/components/wifi/wifi_component_esp_idf.cpp
index 848ec3e11c..99474ac2f8 100644
--- a/esphome/components/wifi/wifi_component_esp_idf.cpp
+++ b/esphome/components/wifi/wifi_component_esp_idf.cpp
@@ -827,16 +827,17 @@ void WiFiComponent::wifi_process_event_(IDFWiFiEvent *data) {
     }
 
     uint16_t number = it.number;
-    auto records = std::make_unique<wifi_ap_record_t[]>(number);
-    err = esp_wifi_scan_get_ap_records(&number, records.get());
-    if (err != ESP_OK) {
-      ESP_LOGW(TAG, "esp_wifi_scan_get_ap_records failed: %s", esp_err_to_name(err));
-      return;
-    }
-
     scan_result_.init(number);
-    for (int i = 0; i < number; i++) {
-      auto &record = records[i];
+
+    // Process one record at a time to avoid large buffer allocation
+    wifi_ap_record_t record;
+    for (uint16_t i = 0; i < number; i++) {
+      err = esp_wifi_scan_get_ap_record(&record);
+      if (err != ESP_OK) {
+        ESP_LOGW(TAG, "esp_wifi_scan_get_ap_record failed: %s", esp_err_to_name(err));
+        esp_wifi_clear_ap_list();  // Free remaining records not yet retrieved
+        break;
+      }
       bssid_t bssid;
       std::copy(record.bssid, record.bssid + 6, bssid.begin());
       std::string ssid(reinterpret_cast<const char *>(record.ssid));
diff --git a/esphome/components/wifi/wifi_component_libretiny.cpp b/esphome/components/wifi/wifi_component_libretiny.cpp
index 162ed4e835..cc9f4ec193 100644
--- a/esphome/components/wifi/wifi_component_libretiny.cpp
+++ b/esphome/components/wifi/wifi_component_libretiny.cpp
@@ -460,13 +460,15 @@ void WiFiComponent::wifi_process_event_(LTWiFiEvent *event) {
         listener->on_wifi_connect_state(StringRef(it.ssid, it.ssid_len), it.bssid);
       }
 #endif
-      // For static IP configurations, GOT_IP event may not fire, so notify IP listeners here
-#if defined(USE_WIFI_IP_STATE_LISTENERS) && defined(USE_WIFI_MANUAL_IP)
+      // For static IP configurations, GOT_IP event may not fire, so set connected state here
+#ifdef USE_WIFI_MANUAL_IP
       if (const WiFiAP *config = this->get_selected_sta_(); config && config->get_manual_ip().has_value()) {
         s_sta_state = LTWiFiSTAState::CONNECTED;
+#ifdef USE_WIFI_IP_STATE_LISTENERS
         for (auto *listener : this->ip_state_listeners_) {
           listener->on_ip_state(this->wifi_sta_ip_addresses(), this->get_dns_address(0), this->get_dns_address(1));
         }
+#endif
       }
 #endif
       break;
diff --git a/esphome/components/wifi_info/text_sensor.py b/esphome/components/wifi_info/text_sensor.py
index 9ecb5b7490..5f72d0aa74 100644
--- a/esphome/components/wifi_info/text_sensor.py
+++ b/esphome/components/wifi_info/text_sensor.py
@@ -79,13 +79,17 @@ async def setup_conf(config, key):
 
 async def to_code(config):
     # Request specific WiFi listeners based on which sensors are configured
+    # Each sensor needs its own listener slot - call request for EACH sensor
+
     # SSID and BSSID use WiFiConnectStateListener
-    if CONF_SSID in config or CONF_BSSID in config:
-        wifi.request_wifi_connect_state_listener()
+    for key in (CONF_SSID, CONF_BSSID):
+        if key in config:
+            wifi.request_wifi_connect_state_listener()
 
     # IP address and DNS use WiFiIPStateListener
-    if CONF_IP_ADDRESS in config or CONF_DNS_ADDRESS in config:
-        wifi.request_wifi_ip_state_listener()
+    for key in (CONF_IP_ADDRESS, CONF_DNS_ADDRESS):
+        if key in config:
+            wifi.request_wifi_ip_state_listener()
 
     # Scan results use WiFiScanResultsListener
     if CONF_SCAN_RESULTS in config:
diff --git a/esphome/components/wireguard/__init__.py b/esphome/components/wireguard/__init__.py
index 50c7980215..124d9a8c32 100644
--- a/esphome/components/wireguard/__init__.py
+++ b/esphome/components/wireguard/__init__.py
@@ -30,6 +30,7 @@ _WG_KEY_REGEX = re.compile(r"^[A-Za-z0-9+/]{42}[AEIMQUYcgkosw480]=$")
 
 wireguard_ns = cg.esphome_ns.namespace("wireguard")
 Wireguard = wireguard_ns.class_("Wireguard", cg.Component, cg.PollingComponent)
+AllowedIP = wireguard_ns.struct("AllowedIP")
 WireguardPeerOnlineCondition = wireguard_ns.class_(
     "WireguardPeerOnlineCondition", automation.Condition
 )
@@ -108,8 +109,18 @@ async def to_code(config):
         )
     )
 
-    for ip in allowed_ips:
-        cg.add(var.add_allowed_ip(str(ip.network_address), str(ip.netmask)))
+    cg.add(
+        var.set_allowed_ips(
+            [
+                cg.StructInitializer(
+                    AllowedIP,
+                    ("ip", str(ip.network_address)),
+                    ("netmask", str(ip.netmask)),
+                )
+                for ip in allowed_ips
+            ]
+        )
+    )
 
     cg.add(var.set_srctime(await cg.get_variable(config[CONF_TIME_ID])))
 
diff --git a/esphome/components/wireguard/wireguard.cpp b/esphome/components/wireguard/wireguard.cpp
index 7810a40ae1..2022e25b6c 100644
--- a/esphome/components/wireguard/wireguard.cpp
+++ b/esphome/components/wireguard/wireguard.cpp
@@ -13,8 +13,7 @@
 #include <esp_wireguard.h>
 #include <esp_wireguard_err.h>
 
-namespace esphome {
-namespace wireguard {
+namespace esphome::wireguard {
 
 static const char *const TAG = "wireguard";
 
@@ -28,16 +27,16 @@ static const char *const LOGMSG_ONLINE = "online";
 static const char *const LOGMSG_OFFLINE = "offline";
 
 void Wireguard::setup() {
-  this->wg_config_.address = this->address_.c_str();
-  this->wg_config_.private_key = this->private_key_.c_str();
-  this->wg_config_.endpoint = this->peer_endpoint_.c_str();
-  this->wg_config_.public_key = this->peer_public_key_.c_str();
+  this->wg_config_.address = this->address_;
+  this->wg_config_.private_key = this->private_key_;
+  this->wg_config_.endpoint = this->peer_endpoint_;
+  this->wg_config_.public_key = this->peer_public_key_;
   this->wg_config_.port = this->peer_port_;
-  this->wg_config_.netmask = this->netmask_.c_str();
+  this->wg_config_.netmask = this->netmask_;
   this->wg_config_.persistent_keepalive = this->keepalive_;
 
-  if (!this->preshared_key_.empty())
-    this->wg_config_.preshared_key = this->preshared_key_.c_str();
+  if (this->preshared_key_ != nullptr)
+    this->wg_config_.preshared_key = this->preshared_key_;
 
   this->publish_enabled_state();
 
@@ -131,6 +130,10 @@ void Wireguard::update() {
 }
 
 void Wireguard::dump_config() {
+  char private_key_masked[MASK_KEY_BUFFER_SIZE];
+  char preshared_key_masked[MASK_KEY_BUFFER_SIZE];
+  mask_key_to(private_key_masked, sizeof(private_key_masked), this->private_key_);
+  mask_key_to(preshared_key_masked, sizeof(preshared_key_masked), this->preshared_key_);
   // clang-format off
   ESP_LOGCONFIG(
       TAG,
@@ -142,13 +145,13 @@ void Wireguard::dump_config() {
       "  Peer Port: " LOG_SECRET("%d") "\n"
       "  Peer Public Key: " LOG_SECRET("%s") "\n"
       "  Peer Pre-shared Key: " LOG_SECRET("%s"),
-      this->address_.c_str(), this->netmask_.c_str(), mask_key(this->private_key_).c_str(),
-      this->peer_endpoint_.c_str(), this->peer_port_, this->peer_public_key_.c_str(),
-      (!this->preshared_key_.empty() ? mask_key(this->preshared_key_).c_str() : "NOT IN USE"));
+      this->address_, this->netmask_, private_key_masked,
+      this->peer_endpoint_, this->peer_port_, this->peer_public_key_,
+      (this->preshared_key_ != nullptr ? preshared_key_masked : "NOT IN USE"));
   // clang-format on
   ESP_LOGCONFIG(TAG, "  Peer Allowed IPs:");
-  for (auto &allowed_ip : this->allowed_ips_) {
-    ESP_LOGCONFIG(TAG, "    - %s/%s", std::get<0>(allowed_ip).c_str(), std::get<1>(allowed_ip).c_str());
+  for (const AllowedIP &allowed_ip : this->allowed_ips_) {
+    ESP_LOGCONFIG(TAG, "    - %s/%s", allowed_ip.ip, allowed_ip.netmask);
   }
   ESP_LOGCONFIG(TAG, "  Peer Persistent Keepalive: %d%s", this->keepalive_,
                 (this->keepalive_ > 0 ? "s" : " (DISABLED)"));
@@ -176,18 +179,6 @@ time_t Wireguard::get_latest_handshake() const {
   return result;
 }
 
-void Wireguard::set_address(const std::string &address) { this->address_ = address; }
-void Wireguard::set_netmask(const std::string &netmask) { this->netmask_ = netmask; }
-void Wireguard::set_private_key(const std::string &key) { this->private_key_ = key; }
-void Wireguard::set_peer_endpoint(const std::string &endpoint) { this->peer_endpoint_ = endpoint; }
-void Wireguard::set_peer_public_key(const std::string &key) { this->peer_public_key_ = key; }
-void Wireguard::set_peer_port(const uint16_t port) { this->peer_port_ = port; }
-void Wireguard::set_preshared_key(const std::string &key) { this->preshared_key_ = key; }
-
-void Wireguard::add_allowed_ip(const std::string &ip, const std::string &netmask) {
-  this->allowed_ips_.emplace_back(ip, netmask);
-}
-
 void Wireguard::set_keepalive(const uint16_t seconds) { this->keepalive_ = seconds; }
 void Wireguard::set_reboot_timeout(const uint32_t seconds) { this->reboot_timeout_ = seconds; }
 void Wireguard::set_srctime(time::RealTimeClock *srctime) { this->srctime_ = srctime; }
@@ -274,9 +265,8 @@ void Wireguard::start_connection_() {
 
   ESP_LOGD(TAG, "Configuring allowed IPs list");
   bool allowed_ips_ok = true;
-  for (std::tuple<std::string, std::string> ip : this->allowed_ips_) {
-    allowed_ips_ok &=
-        (esp_wireguard_add_allowed_ip(&(this->wg_ctx_), std::get<0>(ip).c_str(), std::get<1>(ip).c_str()) == ESP_OK);
+  for (const AllowedIP &ip : this->allowed_ips_) {
+    allowed_ips_ok &= (esp_wireguard_add_allowed_ip(&(this->wg_ctx_), ip.ip, ip.netmask) == ESP_OK);
   }
 
   if (allowed_ips_ok) {
@@ -299,8 +289,25 @@ void Wireguard::stop_connection_() {
   }
 }
 
-std::string mask_key(const std::string &key) { return (key.substr(0, 5) + "[...]="); }
+void mask_key_to(char *buffer, size_t len, const char *key) {
+  // Format: "XXXXX[...]=\0" = MASK_KEY_BUFFER_SIZE chars minimum
+  if (len < MASK_KEY_BUFFER_SIZE || key == nullptr) {
+    if (len > 0)
+      buffer[0] = '\0';
+    return;
+  }
+  // Copy first 5 characters of the key
+  size_t i = 0;
+  for (; i < 5 && key[i] != '\0'; ++i) {
+    buffer[i] = key[i];
+  }
+  // Append "[...]="
+  const char *suffix = "[...]=";
+  for (size_t j = 0; suffix[j] != '\0' && (i + j) < len - 1; ++j) {
+    buffer[i + j] = suffix[j];
+  }
+  buffer[i + 6] = '\0';
+}
 
-}  // namespace wireguard
-}  // namespace esphome
+}  // namespace esphome::wireguard
 #endif
diff --git a/esphome/components/wireguard/wireguard.h b/esphome/components/wireguard/wireguard.h
index f8f79b835d..e8470c75cd 100644
--- a/esphome/components/wireguard/wireguard.h
+++ b/esphome/components/wireguard/wireguard.h
@@ -2,10 +2,10 @@
 #include "esphome/core/defines.h"
 #ifdef USE_WIREGUARD
 #include <ctime>
-#include <vector>
-#include <tuple>
+#include <initializer_list>
 
 #include "esphome/core/component.h"
+#include "esphome/core/helpers.h"
 #include "esphome/components/time/real_time_clock.h"
 
 #ifdef USE_BINARY_SENSOR
@@ -22,8 +22,13 @@
 
 #include <esp_wireguard.h>
 
-namespace esphome {
-namespace wireguard {
+namespace esphome::wireguard {
+
+/// Allowed IP entry for WireGuard peer configuration.
+struct AllowedIP {
+  const char *ip;
+  const char *netmask;
+};
 
 /// Main Wireguard component class.
 class Wireguard : public PollingComponent {
@@ -37,15 +42,25 @@ class Wireguard : public PollingComponent {
 
   float get_setup_priority() const override { return esphome::setup_priority::BEFORE_CONNECTION; }
 
-  void set_address(const std::string &address);
-  void set_netmask(const std::string &netmask);
-  void set_private_key(const std::string &key);
-  void set_peer_endpoint(const std::string &endpoint);
-  void set_peer_public_key(const std::string &key);
-  void set_peer_port(uint16_t port);
-  void set_preshared_key(const std::string &key);
+  void set_address(const char *address) { this->address_ = address; }
+  void set_netmask(const char *netmask) { this->netmask_ = netmask; }
+  void set_private_key(const char *key) { this->private_key_ = key; }
+  void set_peer_endpoint(const char *endpoint) { this->peer_endpoint_ = endpoint; }
+  void set_peer_public_key(const char *key) { this->peer_public_key_ = key; }
+  void set_peer_port(uint16_t port) { this->peer_port_ = port; }
+  void set_preshared_key(const char *key) { this->preshared_key_ = key; }
 
-  void add_allowed_ip(const std::string &ip, const std::string &netmask);
+  /// Prevent accidental use of std::string which would dangle
+  void set_address(const std::string &address) = delete;
+  void set_netmask(const std::string &netmask) = delete;
+  void set_private_key(const std::string &key) = delete;
+  void set_peer_endpoint(const std::string &endpoint) = delete;
+  void set_peer_public_key(const std::string &key) = delete;
+  void set_preshared_key(const std::string &key) = delete;
+
+  void set_allowed_ips(std::initializer_list<AllowedIP> ips) { this->allowed_ips_ = ips; }
+  /// Prevent accidental use of std::string which would dangle
+  void set_allowed_ips(std::initializer_list<std::tuple<std::string, std::string>> ips) = delete;
 
   void set_keepalive(uint16_t seconds);
   void set_reboot_timeout(uint32_t seconds);
@@ -83,14 +98,14 @@ class Wireguard : public PollingComponent {
   time_t get_latest_handshake() const;
 
  protected:
-  std::string address_;
-  std::string netmask_;
-  std::string private_key_;
-  std::string peer_endpoint_;
-  std::string peer_public_key_;
-  std::string preshared_key_;
+  const char *address_{nullptr};
+  const char *netmask_{nullptr};
+  const char *private_key_{nullptr};
+  const char *peer_endpoint_{nullptr};
+  const char *peer_public_key_{nullptr};
+  const char *preshared_key_{nullptr};
 
-  std::vector<std::tuple<std::string, std::string>> allowed_ips_;
+  FixedVector<AllowedIP> allowed_ips_;
 
   uint16_t peer_port_;
   uint16_t keepalive_;
@@ -142,8 +157,11 @@ class Wireguard : public PollingComponent {
 void suspend_wdt();
 void resume_wdt();
 
+/// Size of buffer required for mask_key_to: 5 chars + "[...]=" + null = 12
+static constexpr size_t MASK_KEY_BUFFER_SIZE = 12;
+
 /// Strip most part of the key only for secure printing
-std::string mask_key(const std::string &key);
+void mask_key_to(char *buffer, size_t len, const char *key);
 
 /// Condition to check if remote peer is online.
 template<typename... Ts> class WireguardPeerOnlineCondition : public Condition<Ts...>, public Parented<Wireguard> {
@@ -169,6 +187,5 @@ template<typename... Ts> class WireguardDisableAction : public Action<Ts...>, pu
   void play(const Ts &...x) override { this->parent_->disable(); }
 };
 
-}  // namespace wireguard
-}  // namespace esphome
+}  // namespace esphome::wireguard
 #endif
diff --git a/esphome/components/wl_134/wl_134.cpp b/esphome/components/wl_134/wl_134.cpp
index 20a145d183..a589f71c84 100644
--- a/esphome/components/wl_134/wl_134.cpp
+++ b/esphome/components/wl_134/wl_134.cpp
@@ -1,4 +1,5 @@
 #include "wl_134.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
 #include <cinttypes>
@@ -78,8 +79,8 @@ Wl134Component::Rfid134Error Wl134Component::read_packet_() {
            reading.id, reading.country, reading.isData ? "true" : "false", reading.isAnimal ? "true" : "false",
            reading.reserved0, reading.reserved1);
 
-  char buf[20];
-  sprintf(buf, "%03d%012lld", reading.country, reading.id);
+  char buf[20];  // "%03d" (3) + "%012" PRId64 (12) + null = 16 max
+  buf_append_printf(buf, sizeof(buf), 0, "%03d%012" PRId64, reading.country, reading.id);
   this->publish_state(buf);
   if (this->do_reset_) {
     this->set_timeout(1000, [this]() { this->publish_state(""); });
diff --git a/esphome/components/x9c/x9c.cpp b/esphome/components/x9c/x9c.cpp
index 8f66c46015..773e52d6e1 100644
--- a/esphome/components/x9c/x9c.cpp
+++ b/esphome/components/x9c/x9c.cpp
@@ -6,7 +6,7 @@ namespace x9c {
 
 static const char *const TAG = "x9c.output";
 
-void X9cOutput::trim_value(int change_amount) {
+void X9cOutput::trim_value(int32_t change_amount) {
   if (change_amount == 0) {
     return;
   }
@@ -47,17 +47,17 @@ void X9cOutput::setup() {
 
   if (this->initial_value_ <= 0.50) {
     this->trim_value(-101);  // Set min value (beyond 0)
-    this->trim_value(static_cast<uint32_t>(roundf(this->initial_value_ * 100)));
+    this->trim_value(lroundf(this->initial_value_ * 100));
   } else {
     this->trim_value(101);  // Set max value (beyond 100)
-    this->trim_value(static_cast<uint32_t>(roundf(this->initial_value_ * 100) - 100));
+    this->trim_value(lroundf(this->initial_value_ * 100) - 100);
   }
   this->pot_value_ = this->initial_value_;
   this->write_state(this->initial_value_);
 }
 
 void X9cOutput::write_state(float state) {
-  this->trim_value(static_cast<uint32_t>(roundf((state - this->pot_value_) * 100)));
+  this->trim_value(lroundf((state - this->pot_value_) * 100));
   this->pot_value_ = state;
 }
 
diff --git a/esphome/components/x9c/x9c.h b/esphome/components/x9c/x9c.h
index e7cc29a6cc..66c3df14e1 100644
--- a/esphome/components/x9c/x9c.h
+++ b/esphome/components/x9c/x9c.h
@@ -18,7 +18,7 @@ class X9cOutput : public output::FloatOutput, public Component {
   void setup() override;
   void dump_config() override;
 
-  void trim_value(int change_amount);
+  void trim_value(int32_t change_amount);
 
  protected:
   void write_state(float state) override;
diff --git a/esphome/components/xl9535/xl9535.cpp b/esphome/components/xl9535/xl9535.cpp
index dd6c8188eb..cfcbeeeb8d 100644
--- a/esphome/components/xl9535/xl9535.cpp
+++ b/esphome/components/xl9535/xl9535.cpp
@@ -111,7 +111,7 @@ void XL9535Component::pin_mode(uint8_t pin, gpio::Flags mode) {
 void XL9535GPIOPin::setup() { this->pin_mode(this->flags_); }
 
 size_t XL9535GPIOPin::dump_summary(char *buffer, size_t len) const {
-  return snprintf(buffer, len, "%u via XL9535", this->pin_);
+  return buf_append_printf(buffer, len, 0, "%u via XL9535", this->pin_);
 }
 
 void XL9535GPIOPin::pin_mode(gpio::Flags flags) { this->parent_->pin_mode(this->pin_, flags); }
diff --git a/esphome/components/zephyr/gpio.h b/esphome/components/zephyr/gpio.h
index c9540f4f01..94f25f02ac 100644
--- a/esphome/components/zephyr/gpio.h
+++ b/esphome/components/zephyr/gpio.h
@@ -2,7 +2,7 @@
 
 #ifdef USE_ZEPHYR
 #include "esphome/core/hal.h"
-struct device;
+#include <zephyr/device.h>
 namespace esphome {
 namespace zephyr {
 
diff --git a/esphome/components/zephyr/preferences.cpp b/esphome/components/zephyr/preferences.cpp
index 08b361b8fb..311133a813 100644
--- a/esphome/components/zephyr/preferences.cpp
+++ b/esphome/components/zephyr/preferences.cpp
@@ -5,6 +5,8 @@
 #include "esphome/core/preferences.h"
 #include "esphome/core/log.h"
 #include <zephyr/settings/settings.h>
+#include <cinttypes>
+#include <cstring>
 
 namespace esphome {
 namespace zephyr {
@@ -13,6 +15,9 @@ static const char *const TAG = "zephyr.preferences";
 
 #define ESPHOME_SETTINGS_KEY "esphome"
 
+// Buffer size for key: "esphome/" (8) + max hex uint32 (8) + null terminator (1) = 17; use 20 for safety margin
+static constexpr size_t KEY_BUFFER_SIZE = 20;
+
 class ZephyrPreferenceBackend : public ESPPreferenceBackend {
  public:
   ZephyrPreferenceBackend(uint32_t type) { this->type_ = type; }
@@ -27,7 +32,9 @@ class ZephyrPreferenceBackend : public ESPPreferenceBackend {
 
   bool load(uint8_t *data, size_t len) override {
     if (len != this->data.size()) {
-      ESP_LOGE(TAG, "size of setting key %s changed, from: %u, to: %u", get_key().c_str(), this->data.size(), len);
+      char key_buf[KEY_BUFFER_SIZE];
+      this->format_key(key_buf, sizeof(key_buf));
+      ESP_LOGE(TAG, "size of setting key %s changed, from: %u, to: %u", key_buf, this->data.size(), len);
       return false;
     }
     std::memcpy(data, this->data.data(), len);
@@ -36,7 +43,7 @@ class ZephyrPreferenceBackend : public ESPPreferenceBackend {
   }
 
   uint32_t get_type() const { return this->type_; }
-  std::string get_key() const { return str_sprintf(ESPHOME_SETTINGS_KEY "/%" PRIx32, this->type_); }
+  void format_key(char *buf, size_t size) const { snprintf(buf, size, ESPHOME_SETTINGS_KEY "/%" PRIx32, this->type_); }
 
   std::vector<uint8_t> data;
 
@@ -85,7 +92,9 @@ class ZephyrPreferences : public ESPPreferences {
     }
     printf("type %u size %u\n", type, this->backends_.size());
     auto *pref = new ZephyrPreferenceBackend(type);  // NOLINT(cppcoreguidelines-owning-memory)
-    ESP_LOGD(TAG, "Add new setting %s.", pref->get_key().c_str());
+    char key_buf[KEY_BUFFER_SIZE];
+    pref->format_key(key_buf, sizeof(key_buf));
+    ESP_LOGD(TAG, "Add new setting %s.", key_buf);
     this->backends_.push_back(pref);
     return ESPPreferenceObject(pref);
   }
@@ -134,9 +143,10 @@ class ZephyrPreferences : public ESPPreferences {
 
   static int export_settings(int (*cb)(const char *name, const void *value, size_t val_len)) {
     for (auto *backend : static_cast<ZephyrPreferences *>(global_preferences)->backends_) {
-      auto name = backend->get_key();
-      int err = cb(name.c_str(), backend->data.data(), backend->data.size());
-      ESP_LOGD(TAG, "save in flash, name %s, len %u, err %d", name.c_str(), backend->data.size(), err);
+      char name[KEY_BUFFER_SIZE];
+      backend->format_key(name, sizeof(name));
+      int err = cb(name, backend->data.data(), backend->data.size());
+      ESP_LOGD(TAG, "save in flash, name %s, len %u, err %d", name, backend->data.size(), err);
     }
     return 0;
   }
diff --git a/esphome/config_validation.py b/esphome/config_validation.py
index 8e2fadbea8..b7ab02013d 100644
--- a/esphome/config_validation.py
+++ b/esphome/config_validation.py
@@ -1046,20 +1046,20 @@ def mac_address(value):
     return core.MACAddress(*parts_int)
 
 
-def bind_key(value):
+def bind_key(value, *, name="Bind key"):
     value = string_strict(value)
     parts = [value[i : i + 2] for i in range(0, len(value), 2)]
     if len(parts) != 16:
-        raise Invalid("Bind key must consist of 16 hexadecimal numbers")
+        raise Invalid(f"{name} must consist of 16 hexadecimal numbers")
     parts_int = []
     if any(len(part) != 2 for part in parts):
-        raise Invalid("Bind key must be format XX")
+        raise Invalid(f"{name} must be format XX")
     for part in parts:
         try:
             parts_int.append(int(part, 16))
         except ValueError:
             # pylint: disable=raise-missing-from
-            raise Invalid("Bind key must be hex values from 00 to FF")
+            raise Invalid(f"{name} must be hex values from 00 to FF")
 
     return "".join(f"{part:02X}" for part in parts_int)
 
diff --git a/esphome/const.py b/esphome/const.py
index c88d5811b4..4243b2e25d 100644
--- a/esphome/const.py
+++ b/esphome/const.py
@@ -1086,6 +1086,7 @@ CONF_WAKEUP_PIN = "wakeup_pin"
 CONF_WAND_ID = "wand_id"
 CONF_WARM_WHITE = "warm_white"
 CONF_WARM_WHITE_COLOR_TEMPERATURE = "warm_white_color_temperature"
+CONF_WARMUP_TIME = "warmup_time"
 CONF_WATCHDOG_THRESHOLD = "watchdog_threshold"
 CONF_WATCHDOG_TIMEOUT = "watchdog_timeout"
 CONF_WATER_HEATER = "water_heater"
@@ -1379,6 +1380,7 @@ KEY_FRAMEWORK_VERSION = "framework_version"
 KEY_NAME = "name"
 KEY_VARIANT = "variant"
 KEY_PAST_SAFE_MODE = "past_safe_mode"
+KEY_NATIVE_IDF = "native_idf"
 
 # Entity categories
 ENTITY_CATEGORY_NONE = ""
diff --git a/esphome/core/__init__.py b/esphome/core/__init__.py
index 70593d8153..9a7dd49609 100644
--- a/esphome/core/__init__.py
+++ b/esphome/core/__init__.py
@@ -17,6 +17,7 @@ from esphome.const import (
     CONF_WEB_SERVER,
     CONF_WIFI,
     KEY_CORE,
+    KEY_NATIVE_IDF,
     KEY_TARGET_FRAMEWORK,
     KEY_TARGET_PLATFORM,
     PLATFORM_BK72XX,
@@ -763,6 +764,9 @@ class EsphomeCore:
 
     @property
     def firmware_bin(self) -> Path:
+        # Check if using native ESP-IDF build (--native-idf)
+        if self.data.get(KEY_NATIVE_IDF, False):
+            return self.relative_build_path("build", f"{self.name}.bin")
         if self.is_libretiny:
             return self.relative_pioenvs_path(self.name, "firmware.uf2")
         return self.relative_pioenvs_path(self.name, "firmware.bin")
diff --git a/esphome/core/automation.h b/esphome/core/automation.h
index eac469d0fc..31a2fc06f4 100644
--- a/esphome/core/automation.h
+++ b/esphome/core/automation.h
@@ -4,6 +4,7 @@
 #include "esphome/core/defines.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/preferences.h"
+#include "esphome/core/string_ref.h"
 #include <concepts>
 #include <functional>
 #include <utility>
@@ -190,15 +191,55 @@ template<typename T, typename... X> class TemplatableValue {
   /// Get the static string pointer (only valid if is_static_string() returns true)
   const char *get_static_string() const { return this->static_str_; }
 
- protected:
-  enum : uint8_t {
-    NONE,
-    VALUE,
-    LAMBDA,
-    STATELESS_LAMBDA,
-    STATIC_STRING,  // For const char* when T is std::string - avoids heap allocation
-  } type_;
+  /// Check if the string value is empty without allocating (for std::string specialization).
+  /// For NONE, returns true. For STATIC_STRING/VALUE, checks without allocation.
+  /// For LAMBDA/STATELESS_LAMBDA, must call value() which may allocate.
+  bool is_empty() const requires std::same_as<T, std::string> {
+    switch (this->type_) {
+      case NONE:
+        return true;
+      case STATIC_STRING:
+        return this->static_str_ == nullptr || this->static_str_[0] == '\0';
+      case VALUE:
+        return this->value_->empty();
+      default:  // LAMBDA/STATELESS_LAMBDA - must call value()
+        return this->value().empty();
+    }
+  }
 
+  /// Get a StringRef to the string value without heap allocation when possible.
+  /// For STATIC_STRING/VALUE, returns reference to existing data (no allocation).
+  /// For LAMBDA/STATELESS_LAMBDA, calls value(), copies to provided buffer, returns ref to buffer.
+  /// @param lambda_buf Buffer used only for lambda case (must remain valid while StringRef is used).
+  /// @param lambda_buf_size Size of the buffer.
+  /// @return StringRef pointing to the string data.
+  StringRef ref_or_copy_to(char *lambda_buf, size_t lambda_buf_size) const requires std::same_as<T, std::string> {
+    switch (this->type_) {
+      case NONE:
+        return StringRef();
+      case STATIC_STRING:
+        if (this->static_str_ == nullptr)
+          return StringRef();
+        return StringRef(this->static_str_, strlen(this->static_str_));
+      case VALUE:
+        return StringRef(this->value_->data(), this->value_->size());
+      default: {  // LAMBDA/STATELESS_LAMBDA - must call value() and copy
+        std::string result = this->value();
+        size_t copy_len = std::min(result.size(), lambda_buf_size - 1);
+        memcpy(lambda_buf, result.data(), copy_len);
+        lambda_buf[copy_len] = '\0';
+        return StringRef(lambda_buf, copy_len);
+      }
+    }
+  }
+
+ protected : enum : uint8_t {
+   NONE,
+   VALUE,
+   LAMBDA,
+   STATELESS_LAMBDA,
+   STATIC_STRING,  // For const char* when T is std::string - avoids heap allocation
+ } type_;
   // For std::string, use heap pointer to minimize union size (4 bytes vs 12+).
   // For other types, store value inline as before.
   using ValueStorage = std::conditional_t<USE_HEAP_STORAGE, T *, T>;
diff --git a/esphome/core/component.cpp b/esphome/core/component.cpp
index 2f61f7d195..98e8c02d07 100644
--- a/esphome/core/component.cpp
+++ b/esphome/core/component.cpp
@@ -47,18 +47,21 @@ struct ComponentPriorityOverride {
 };
 
 // Error messages for failed components
+// Using raw pointer instead of unique_ptr to avoid global constructor/destructor overhead
+// This is never freed as error messages persist for the lifetime of the device
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
-std::unique_ptr<std::vector<ComponentErrorMessage>> component_error_messages;
+std::vector<ComponentErrorMessage> *component_error_messages = nullptr;
 // Setup priority overrides - freed after setup completes
+// Using raw pointer instead of unique_ptr to avoid global constructor/destructor overhead
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
-std::unique_ptr<std::vector<ComponentPriorityOverride>> setup_priority_overrides;
+std::vector<ComponentPriorityOverride> *setup_priority_overrides = nullptr;
 
 // Helper to store error messages - reduces duplication between deprecated and new API
 // Remove before 2026.6.0 when deprecated const char* API is removed
 void store_component_error_message(const Component *component, const char *message, bool is_flash_ptr) {
   // Lazy allocate the error messages vector if needed
   if (!component_error_messages) {
-    component_error_messages = std::make_unique<std::vector<ComponentErrorMessage>>();
+    component_error_messages = new std::vector<ComponentErrorMessage>();
   }
   // Check if this component already has an error message
   for (auto &entry : *component_error_messages) {
@@ -467,7 +470,7 @@ float Component::get_actual_setup_priority() const {
 void Component::set_setup_priority(float priority) {
   // Lazy allocate the vector if needed
   if (!setup_priority_overrides) {
-    setup_priority_overrides = std::make_unique<std::vector<ComponentPriorityOverride>>();
+    setup_priority_overrides = new std::vector<ComponentPriorityOverride>();
     // Reserve some space to avoid reallocations (most configs have < 10 overrides)
     setup_priority_overrides->reserve(10);
   }
@@ -553,7 +556,8 @@ WarnIfComponentBlockingGuard::~WarnIfComponentBlockingGuard() {}
 
 void clear_setup_priority_overrides() {
   // Free the setup priority map completely
-  setup_priority_overrides.reset();
+  delete setup_priority_overrides;
+  setup_priority_overrides = nullptr;
 }
 
 }  // namespace esphome
diff --git a/esphome/core/defines.h b/esphome/core/defines.h
index c229d1df7d..7c13823fba 100644
--- a/esphome/core/defines.h
+++ b/esphome/core/defines.h
@@ -234,7 +234,7 @@
 #define USB_HOST_MAX_REQUESTS 16
 
 #ifdef USE_ARDUINO
-#define USE_ARDUINO_VERSION_CODE VERSION_CODE(3, 3, 5)
+#define USE_ARDUINO_VERSION_CODE VERSION_CODE(3, 3, 6)
 #define USE_ETHERNET
 #define USE_ETHERNET_KSZ8081
 #define USE_ETHERNET_MANUAL_IP
diff --git a/esphome/core/helpers.cpp b/esphome/core/helpers.cpp
index 5cad2308df..e7b901d71f 100644
--- a/esphome/core/helpers.cpp
+++ b/esphome/core/helpers.cpp
@@ -174,6 +174,13 @@ bool str_endswith(const std::string &str, const std::string &end) {
   return str.rfind(end) == (str.size() - end.size());
 }
 #endif
+
+bool str_endswith_ignore_case(const char *str, size_t str_len, const char *suffix, size_t suffix_len) {
+  if (suffix_len > str_len)
+    return false;
+  return strncasecmp(str + str_len - suffix_len, suffix, suffix_len) == 0;
+}
+
 std::string str_truncate(const std::string &str, size_t length) {
   return str.length() > length ? str.substr(0, length) : str;
 }
@@ -199,11 +206,22 @@ std::string str_snake_case(const std::string &str) {
   }
   return result;
 }
-std::string str_sanitize(const std::string &str) {
-  std::string result = str;
-  for (char &c : result) {
-    c = to_sanitized_char(c);
+char *str_sanitize_to(char *buffer, size_t buffer_size, const char *str) {
+  if (buffer_size == 0) {
+    return buffer;
   }
+  size_t i = 0;
+  while (*str && i < buffer_size - 1) {
+    buffer[i++] = to_sanitized_char(*str++);
+  }
+  buffer[i] = '\0';
+  return buffer;
+}
+
+std::string str_sanitize(const std::string &str) {
+  std::string result;
+  result.resize(str.size());
+  str_sanitize_to(&result[0], str.size() + 1, str.c_str());
   return result;
 }
 std::string str_snprintf(const char *fmt, size_t len, ...) {
@@ -404,15 +422,31 @@ std::string format_hex_pretty(const std::string &data, char separator, bool show
   return format_hex_pretty_uint8(reinterpret_cast<const uint8_t *>(data.data()), data.length(), separator, show_length);
 }
 
+char *format_bin_to(char *buffer, size_t buffer_size, const uint8_t *data, size_t length) {
+  if (buffer_size == 0) {
+    return buffer;
+  }
+  // Calculate max bytes we can format: each byte needs 8 chars
+  size_t max_bytes = (buffer_size - 1) / 8;
+  if (max_bytes == 0 || length == 0) {
+    buffer[0] = '\0';
+    return buffer;
+  }
+  size_t bytes_to_format = std::min(length, max_bytes);
+
+  for (size_t byte_idx = 0; byte_idx < bytes_to_format; byte_idx++) {
+    for (size_t bit_idx = 0; bit_idx < 8; bit_idx++) {
+      buffer[byte_idx * 8 + bit_idx] = ((data[byte_idx] >> (7 - bit_idx)) & 1) + '0';
+    }
+  }
+  buffer[bytes_to_format * 8] = '\0';
+  return buffer;
+}
+
 std::string format_bin(const uint8_t *data, size_t length) {
   std::string result;
   result.resize(length * 8);
-  for (size_t byte_idx = 0; byte_idx < length; byte_idx++) {
-    for (size_t bit_idx = 0; bit_idx < 8; bit_idx++) {
-      result[byte_idx * 8 + bit_idx] = ((data[byte_idx] >> (7 - bit_idx)) & 1) + '0';
-    }
-  }
-
+  format_bin_to(&result[0], length * 8 + 1, data, length);
   return result;
 }
 
@@ -664,55 +698,6 @@ bool base64_decode_int32_vector(const std::string &base64, std::vector<int32_t>
   return !out.empty();
 }
 
-/// Encode int32 to 5 base85 characters + null terminator
-/// Standard ASCII85 alphabet: '!' (33) = 0 through 'u' (117) = 84
-inline void base85_encode_int32(int32_t value, std::span<char, BASE85_INT32_ENCODED_SIZE> output) {
-  uint32_t v = static_cast<uint32_t>(value);
-  // Encode least significant digit first, then reverse
-  for (int i = 4; i >= 0; i--) {
-    output[i] = static_cast<char>('!' + (v % 85));
-    v /= 85;
-  }
-  output[5] = '\0';
-}
-
-/// Decode 5 base85 characters to int32
-inline bool base85_decode_int32(const char *input, int32_t &out) {
-  uint8_t c0 = static_cast<uint8_t>(input[0] - '!');
-  uint8_t c1 = static_cast<uint8_t>(input[1] - '!');
-  uint8_t c2 = static_cast<uint8_t>(input[2] - '!');
-  uint8_t c3 = static_cast<uint8_t>(input[3] - '!');
-  uint8_t c4 = static_cast<uint8_t>(input[4] - '!');
-
-  // Each digit must be 0-84. Since uint8_t wraps, chars below '!' become > 84
-  if (c0 > 84 || c1 > 84 || c2 > 84 || c3 > 84 || c4 > 84)
-    return false;
-
-  // 85^4 = 52200625, 85^3 = 614125, 85^2 = 7225, 85^1 = 85
-  out = static_cast<int32_t>(c0 * 52200625u + c1 * 614125u + c2 * 7225u + c3 * 85u + c4);
-  return true;
-}
-
-/// Decode base85 string directly into vector (no intermediate buffer)
-bool base85_decode_int32_vector(const std::string &base85, std::vector<int32_t> &out) {
-  size_t len = base85.size();
-  if (len % 5 != 0)
-    return false;
-
-  out.clear();
-  const char *ptr = base85.data();
-  const char *end = ptr + len;
-
-  while (ptr < end) {
-    int32_t value;
-    if (!base85_decode_int32(ptr, value))
-      return false;
-    out.push_back(value);
-    ptr += 5;
-  }
-  return true;
-}
-
 // Colors
 
 float gamma_correct(float value, float gamma) {
diff --git a/esphome/core/helpers.h b/esphome/core/helpers.h
index 000762c9bf..1aa29fa3f7 100644
--- a/esphome/core/helpers.h
+++ b/esphome/core/helpers.h
@@ -17,6 +17,8 @@
 #include <vector>
 #include <concepts>
 
+#include <strings.h>
+
 #include "esphome/core/optional.h"
 
 #ifdef USE_ESP8266
@@ -348,6 +350,8 @@ template<typename T> class FixedVector {
 
   size_t size() const { return size_; }
   bool empty() const { return size_ == 0; }
+  size_t capacity() const { return capacity_; }
+  bool full() const { return size_ == capacity_; }
 
   /// Access element without bounds checking (matches std::vector behavior)
   /// Caller must ensure index is valid (i < size())
@@ -366,6 +370,37 @@ template<typename T> class FixedVector {
   const T *end() const { return data_ + size_; }
 };
 
+/// @brief Helper class for efficient buffer allocation - uses stack for small sizes, heap for large
+/// This is useful when most operations need a small buffer but occasionally need larger ones.
+/// The stack buffer avoids heap allocation in the common case, while heap fallback handles edge cases.
+/// @tparam STACK_SIZE Number of elements in the stack buffer
+/// @tparam T Element type (default: uint8_t)
+template<size_t STACK_SIZE, typename T = uint8_t> class SmallBufferWithHeapFallback {
+ public:
+  explicit SmallBufferWithHeapFallback(size_t size) {
+    if (size <= STACK_SIZE) {
+      this->buffer_ = this->stack_buffer_;
+    } else {
+      this->heap_buffer_ = new T[size];
+      this->buffer_ = this->heap_buffer_;
+    }
+  }
+  ~SmallBufferWithHeapFallback() { delete[] this->heap_buffer_; }
+
+  // Delete copy and move operations to prevent double-delete
+  SmallBufferWithHeapFallback(const SmallBufferWithHeapFallback &) = delete;
+  SmallBufferWithHeapFallback &operator=(const SmallBufferWithHeapFallback &) = delete;
+  SmallBufferWithHeapFallback(SmallBufferWithHeapFallback &&) = delete;
+  SmallBufferWithHeapFallback &operator=(SmallBufferWithHeapFallback &&) = delete;
+
+  T *get() { return this->buffer_; }
+
+ private:
+  T stack_buffer_[STACK_SIZE];
+  T *heap_buffer_{nullptr};
+  T *buffer_;
+};
+
 ///@}
 
 /// @name Mathematics
@@ -395,6 +430,28 @@ constexpr uint32_t FNV1_OFFSET_BASIS = 2166136261UL;
 /// FNV-1 32-bit prime
 constexpr uint32_t FNV1_PRIME = 16777619UL;
 
+/// Extend a FNV-1 hash with an integer (hashes each byte).
+template<std::integral T> constexpr uint32_t fnv1_hash_extend(uint32_t hash, T value) {
+  using UnsignedT = std::make_unsigned_t<T>;
+  UnsignedT uvalue = static_cast<UnsignedT>(value);
+  for (size_t i = 0; i < sizeof(T); i++) {
+    hash *= FNV1_PRIME;
+    hash ^= (uvalue >> (i * 8)) & 0xFF;
+  }
+  return hash;
+}
+/// Extend a FNV-1 hash with additional string data.
+constexpr uint32_t fnv1_hash_extend(uint32_t hash, const char *str) {
+  if (str) {
+    while (*str) {
+      hash *= FNV1_PRIME;
+      hash ^= *str++;
+    }
+  }
+  return hash;
+}
+inline uint32_t fnv1_hash_extend(uint32_t hash, const std::string &str) { return fnv1_hash_extend(hash, str.c_str()); }
+
 /// Extend a FNV-1a hash with additional string data.
 constexpr uint32_t fnv1a_hash_extend(uint32_t hash, const char *str) {
   if (str) {
@@ -517,12 +574,25 @@ template<typename T> constexpr T convert_little_endian(T val) {
 bool str_equals_case_insensitive(const std::string &a, const std::string &b);
 /// Compare StringRefs for equality in case-insensitive manner.
 bool str_equals_case_insensitive(StringRef a, StringRef b);
+/// Compare C strings for equality in case-insensitive manner (no heap allocation).
+inline bool str_equals_case_insensitive(const char *a, const char *b) { return strcasecmp(a, b) == 0; }
+inline bool str_equals_case_insensitive(const std::string &a, const char *b) { return strcasecmp(a.c_str(), b) == 0; }
+inline bool str_equals_case_insensitive(const char *a, const std::string &b) { return strcasecmp(a, b.c_str()) == 0; }
 
 /// Check whether a string starts with a value.
 bool str_startswith(const std::string &str, const std::string &start);
 /// Check whether a string ends with a value.
 bool str_endswith(const std::string &str, const std::string &end);
 
+/// Case-insensitive check if string ends with suffix (no heap allocation).
+bool str_endswith_ignore_case(const char *str, size_t str_len, const char *suffix, size_t suffix_len);
+inline bool str_endswith_ignore_case(const char *str, const char *suffix) {
+  return str_endswith_ignore_case(str, strlen(str), suffix, strlen(suffix));
+}
+inline bool str_endswith_ignore_case(const std::string &str, const char *suffix) {
+  return str_endswith_ignore_case(str.c_str(), str.size(), suffix, strlen(suffix));
+}
+
 /// Truncate a string to a specific length.
 /// @warning Allocates heap memory. Avoid in new code - causes heap fragmentation on long-running devices.
 std::string str_truncate(const std::string &str, size_t length);
@@ -549,7 +619,25 @@ std::string str_snake_case(const std::string &str);
 constexpr char to_sanitized_char(char c) {
   return (c == '-' || c == '_' || (c >= '0' && c <= '9') || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) ? c : '_';
 }
+
+/** Sanitize a string to buffer, keeping only alphanumerics, dashes, and underscores.
+ *
+ * @param buffer Output buffer to write to.
+ * @param buffer_size Size of the output buffer.
+ * @param str Input string to sanitize.
+ * @return Pointer to buffer.
+ *
+ * Buffer size needed: strlen(str) + 1.
+ */
+char *str_sanitize_to(char *buffer, size_t buffer_size, const char *str);
+
+/// Sanitize a string to buffer. Automatically deduces buffer size.
+template<size_t N> inline char *str_sanitize_to(char (&buffer)[N], const char *str) {
+  return str_sanitize_to(buffer, N, str);
+}
+
 /// Sanitizes the input string by removing all characters but alphanumerics, dashes and underscores.
+/// @warning Allocates heap memory. Use str_sanitize_to() with a stack buffer instead.
 std::string str_sanitize(const std::string &str);
 
 /// Calculate FNV-1 hash of a string while applying snake_case + sanitize transformations.
@@ -1096,9 +1184,66 @@ std::string format_hex_pretty(T val, char separator = '.', bool show_length = tr
   return format_hex_pretty(reinterpret_cast<uint8_t *>(&val), sizeof(T), separator, show_length);
 }
 
+/// Calculate buffer size needed for format_bin_to: "01234567...\0" = bytes * 8 + 1
+constexpr size_t format_bin_size(size_t byte_count) { return byte_count * 8 + 1; }
+
+/** Format byte array as binary string to buffer.
+ *
+ * Each byte is formatted as 8 binary digits (MSB first).
+ * Truncates output if data exceeds buffer capacity.
+ *
+ * @param buffer Output buffer to write to.
+ * @param buffer_size Size of the output buffer.
+ * @param data Pointer to the byte array to format.
+ * @param length Number of bytes in the array.
+ * @return Pointer to buffer.
+ *
+ * Buffer size needed: length * 8 + 1 (use format_bin_size()).
+ *
+ * Example:
+ * @code
+ * char buf[9];  // format_bin_size(1)
+ * format_bin_to(buf, sizeof(buf), data, 1);  // "10101011"
+ * @endcode
+ */
+char *format_bin_to(char *buffer, size_t buffer_size, const uint8_t *data, size_t length);
+
+/// Format byte array as binary to buffer. Automatically deduces buffer size.
+template<size_t N> inline char *format_bin_to(char (&buffer)[N], const uint8_t *data, size_t length) {
+  static_assert(N >= 9, "Buffer must hold at least one binary byte (9 chars)");
+  return format_bin_to(buffer, N, data, length);
+}
+
+/** Format an unsigned integer in binary to buffer, MSB first.
+ *
+ * @tparam N Buffer size (must be >= sizeof(T) * 8 + 1).
+ * @tparam T Unsigned integer type.
+ * @param buffer Output buffer to write to.
+ * @param val The unsigned integer value to format.
+ * @return Pointer to buffer.
+ *
+ * Example:
+ * @code
+ * char buf[9];  // format_bin_size(sizeof(uint8_t))
+ * format_bin_to(buf, uint8_t{0xAA});  // "10101010"
+ * char buf16[17];  // format_bin_size(sizeof(uint16_t))
+ * format_bin_to(buf16, uint16_t{0x1234});  // "0001001000110100"
+ * @endcode
+ */
+template<size_t N, typename T, enable_if_t<std::is_unsigned<T>::value, int> = 0>
+inline char *format_bin_to(char (&buffer)[N], T val) {
+  static_assert(N >= sizeof(T) * 8 + 1, "Buffer too small for type");
+  val = convert_big_endian(val);
+  return format_bin_to(buffer, reinterpret_cast<const uint8_t *>(&val), sizeof(T));
+}
+
 /// Format the byte array \p data of length \p len in binary.
+/// @warning Allocates heap memory. Use format_bin_to() with a stack buffer instead.
+/// Causes heap fragmentation on long-running devices.
 std::string format_bin(const uint8_t *data, size_t length);
 /// Format an unsigned integer in binary, starting with the most significant byte.
+/// @warning Allocates heap memory. Use format_bin_to() with a stack buffer instead.
+/// Causes heap fragmentation on long-running devices.
 template<typename T, enable_if_t<std::is_unsigned<T>::value, int> = 0> std::string format_bin(T val) {
   val = convert_big_endian(val);
   return format_bin(reinterpret_cast<uint8_t *>(&val), sizeof(T));
@@ -1143,14 +1288,6 @@ size_t base64_decode(const uint8_t *encoded_data, size_t encoded_len, uint8_t *b
 /// @return true if successful, false if decode failed or invalid size
 bool base64_decode_int32_vector(const std::string &base64, std::vector<int32_t> &out);
 
-/// Size of buffer needed for base85 encoded int32 (5 chars + null terminator)
-static constexpr size_t BASE85_INT32_ENCODED_SIZE = 6;
-
-void base85_encode_int32(int32_t value, std::span<char, BASE85_INT32_ENCODED_SIZE> output);
-
-bool base85_decode_int32(const char *input, int32_t &out);
-bool base85_decode_int32_vector(const std::string &base85, std::vector<int32_t> &out);
-
 ///@}
 
 /// @name Colors
@@ -1216,16 +1353,30 @@ template<typename... X> class LazyCallbackManager;
  *
  * Memory overhead comparison (32-bit systems):
  * - CallbackManager: 12 bytes (empty std::vector)
- * - LazyCallbackManager: 4 bytes (nullptr unique_ptr)
+ * - LazyCallbackManager: 4 bytes (nullptr pointer)
+ *
+ * Uses plain pointer instead of unique_ptr to avoid template instantiation overhead.
+ * The class is explicitly non-copyable/non-movable for Rule of Five compliance.
  *
  * @tparam Ts The arguments for the callbacks, wrapped in void().
  */
 template<typename... Ts> class LazyCallbackManager<void(Ts...)> {
  public:
+  LazyCallbackManager() = default;
+  /// Destructor - clean up allocated CallbackManager if any.
+  /// In practice this never runs (entities live for device lifetime) but included for correctness.
+  ~LazyCallbackManager() { delete this->callbacks_; }
+
+  // Non-copyable and non-movable (entities are never copied or moved)
+  LazyCallbackManager(const LazyCallbackManager &) = delete;
+  LazyCallbackManager &operator=(const LazyCallbackManager &) = delete;
+  LazyCallbackManager(LazyCallbackManager &&) = delete;
+  LazyCallbackManager &operator=(LazyCallbackManager &&) = delete;
+
   /// Add a callback to the list. Allocates the underlying CallbackManager on first use.
   void add(std::function<void(Ts...)> &&callback) {
     if (!this->callbacks_) {
-      this->callbacks_ = make_unique<CallbackManager<void(Ts...)>>();
+      this->callbacks_ = new CallbackManager<void(Ts...)>();
     }
     this->callbacks_->add(std::move(callback));
   }
@@ -1247,7 +1398,7 @@ template<typename... Ts> class LazyCallbackManager<void(Ts...)> {
   void operator()(Ts... args) { this->call(args...); }
 
  protected:
-  std::unique_ptr<CallbackManager<void(Ts...)>> callbacks_;
+  CallbackManager<void(Ts...)> *callbacks_{nullptr};
 };
 
 /// Helper class to deduplicate items in a series of values.
diff --git a/esphome/core/progmem.h b/esphome/core/progmem.h
index fe9c9b5a75..6c3e4cec96 100644
--- a/esphome/core/progmem.h
+++ b/esphome/core/progmem.h
@@ -12,6 +12,8 @@
 #define ESPHOME_strncpy_P strncpy_P
 #define ESPHOME_strncat_P strncat_P
 #define ESPHOME_snprintf_P snprintf_P
+// Type for pointers to PROGMEM strings (for use with ESPHOME_F return values)
+using ProgmemStr = const __FlashStringHelper *;
 #else
 #define ESPHOME_F(string_literal) (string_literal)
 #define ESPHOME_PGM_P const char *
@@ -19,4 +21,6 @@
 #define ESPHOME_strncpy_P strncpy
 #define ESPHOME_strncat_P strncat
 #define ESPHOME_snprintf_P snprintf
+// Type for pointers to strings (no PROGMEM on non-ESP8266 platforms)
+using ProgmemStr = const char *;
 #endif
diff --git a/esphome/core/scheduler.h b/esphome/core/scheduler.h
index 8c2e349180..7de1023e6d 100644
--- a/esphome/core/scheduler.h
+++ b/esphome/core/scheduler.h
@@ -403,7 +403,9 @@ class Scheduler {
       for (size_t i = 0; i < remaining; i++) {
         this->defer_queue_[i] = std::move(this->defer_queue_[this->defer_queue_front_ + i]);
       }
-      this->defer_queue_.resize(remaining);
+      // Use erase() instead of resize() to avoid instantiating _M_default_append
+      // (saves ~156 bytes flash). Erasing from the end is O(1) - no shifting needed.
+      this->defer_queue_.erase(this->defer_queue_.begin() + remaining, this->defer_queue_.end());
     }
     this->defer_queue_front_ = 0;
   }
diff --git a/esphome/core/string_ref.h b/esphome/core/string_ref.h
index 44ca79c81b..d502c4d27f 100644
--- a/esphome/core/string_ref.h
+++ b/esphome/core/string_ref.h
@@ -72,6 +72,7 @@ class StringRef {
 
   constexpr const char *c_str() const { return base_; }
   constexpr size_type size() const { return len_; }
+  constexpr size_type length() const { return len_; }
   constexpr bool empty() const { return len_ == 0; }
   constexpr const_reference operator[](size_type pos) const { return *(base_ + pos); }
 
@@ -80,6 +81,32 @@ class StringRef {
 
   operator std::string() const { return str(); }
 
+  /// Find first occurrence of substring, returns std::string::npos if not found.
+  /// Note: Requires the underlying string to be null-terminated.
+  size_type find(const char *s, size_type pos = 0) const {
+    if (pos >= len_)
+      return std::string::npos;
+    const char *result = std::strstr(base_ + pos, s);
+    // Verify entire match is within bounds (strstr searches to null terminator)
+    if (result && result + std::strlen(s) <= base_ + len_)
+      return static_cast<size_type>(result - base_);
+    return std::string::npos;
+  }
+  size_type find(char c, size_type pos = 0) const {
+    if (pos >= len_)
+      return std::string::npos;
+    const void *result = std::memchr(base_ + pos, static_cast<unsigned char>(c), len_ - pos);
+    return result ? static_cast<size_type>(static_cast<const char *>(result) - base_) : std::string::npos;
+  }
+
+  /// Return substring as std::string
+  std::string substr(size_type pos = 0, size_type count = std::string::npos) const {
+    if (pos >= len_)
+      return std::string();
+    size_type actual_count = (count == std::string::npos || pos + count > len_) ? len_ - pos : count;
+    return std::string(base_ + pos, actual_count);
+  }
+
  private:
   const char *base_;
   size_type len_;
@@ -160,6 +187,43 @@ inline std::string operator+(const std::string &lhs, const StringRef &rhs) {
   str.append(rhs.c_str(), rhs.size());
   return str;
 }
+// String conversion functions for ADL compatibility (allows stoi(x) where x is StringRef)
+// Must be in esphome namespace for ADL to find them. Uses strtol/strtod directly to avoid heap allocation.
+namespace internal {
+// NOLINTBEGIN(google-runtime-int)
+template<typename R, typename F> inline R parse_number(const StringRef &str, size_t *pos, F conv) {
+  char *end;
+  R result = conv(str.c_str(), &end);
+  // Set pos to 0 on conversion failure (when no characters consumed), otherwise index after number
+  if (pos)
+    *pos = (end == str.c_str()) ? 0 : static_cast<size_t>(end - str.c_str());
+  return result;
+}
+template<typename R, typename F> inline R parse_number(const StringRef &str, size_t *pos, int base, F conv) {
+  char *end;
+  R result = conv(str.c_str(), &end, base);
+  // Set pos to 0 on conversion failure (when no characters consumed), otherwise index after number
+  if (pos)
+    *pos = (end == str.c_str()) ? 0 : static_cast<size_t>(end - str.c_str());
+  return result;
+}
+// NOLINTEND(google-runtime-int)
+}  // namespace internal
+// NOLINTBEGIN(readability-identifier-naming,google-runtime-int)
+inline int stoi(const StringRef &str, size_t *pos = nullptr, int base = 10) {
+  return static_cast<int>(internal::parse_number<long>(str, pos, base, std::strtol));
+}
+inline long stol(const StringRef &str, size_t *pos = nullptr, int base = 10) {
+  return internal::parse_number<long>(str, pos, base, std::strtol);
+}
+inline float stof(const StringRef &str, size_t *pos = nullptr) {
+  return internal::parse_number<float>(str, pos, std::strtof);
+}
+inline double stod(const StringRef &str, size_t *pos = nullptr) {
+  return internal::parse_number<double>(str, pos, std::strtod);
+}
+// NOLINTEND(readability-identifier-naming,google-runtime-int)
+
 #ifdef USE_JSON
 // NOLINTNEXTLINE(readability-identifier-naming)
 inline void convertToJson(const StringRef &src, JsonVariant dst) { dst.set(src.c_str()); }
diff --git a/esphome/core/time.cpp b/esphome/core/time.cpp
index 4047033f84..554431c631 100644
--- a/esphome/core/time.cpp
+++ b/esphome/core/time.cpp
@@ -67,7 +67,7 @@ std::string ESPTime::strftime(const char *format) {
 
 std::string ESPTime::strftime(const std::string &format) { return this->strftime(format.c_str()); }
 
-bool ESPTime::strptime(const std::string &time_to_parse, ESPTime &esp_time) {
+bool ESPTime::strptime(const char *time_to_parse, size_t len, ESPTime &esp_time) {
   uint16_t year;
   uint8_t month;
   uint8_t day;
@@ -75,40 +75,41 @@ bool ESPTime::strptime(const std::string &time_to_parse, ESPTime &esp_time) {
   uint8_t minute;
   uint8_t second;
   int num;
+  const int ilen = static_cast<int>(len);
 
-  if (sscanf(time_to_parse.c_str(), "%04hu-%02hhu-%02hhu %02hhu:%02hhu:%02hhu %n", &year, &month, &day,  // NOLINT
-             &hour,                                                                                      // NOLINT
-             &minute,                                                                                    // NOLINT
-             &second, &num) == 6 &&                                                                      // NOLINT
-      num == static_cast<int>(time_to_parse.size())) {
+  if (sscanf(time_to_parse, "%04hu-%02hhu-%02hhu %02hhu:%02hhu:%02hhu %n", &year, &month, &day,  // NOLINT
+             &hour,                                                                              // NOLINT
+             &minute,                                                                            // NOLINT
+             &second, &num) == 6 &&                                                              // NOLINT
+      num == ilen) {
     esp_time.year = year;
     esp_time.month = month;
     esp_time.day_of_month = day;
     esp_time.hour = hour;
     esp_time.minute = minute;
     esp_time.second = second;
-  } else if (sscanf(time_to_parse.c_str(), "%04hu-%02hhu-%02hhu %02hhu:%02hhu %n", &year, &month, &day,  // NOLINT
-                    &hour,                                                                               // NOLINT
-                    &minute, &num) == 5 &&                                                               // NOLINT
-             num == static_cast<int>(time_to_parse.size())) {
+  } else if (sscanf(time_to_parse, "%04hu-%02hhu-%02hhu %02hhu:%02hhu %n", &year, &month, &day,  // NOLINT
+                    &hour,                                                                       // NOLINT
+                    &minute, &num) == 5 &&                                                       // NOLINT
+             num == ilen) {
     esp_time.year = year;
     esp_time.month = month;
     esp_time.day_of_month = day;
     esp_time.hour = hour;
     esp_time.minute = minute;
     esp_time.second = 0;
-  } else if (sscanf(time_to_parse.c_str(), "%02hhu:%02hhu:%02hhu %n", &hour, &minute, &second, &num) == 3 &&  // NOLINT
-             num == static_cast<int>(time_to_parse.size())) {
+  } else if (sscanf(time_to_parse, "%02hhu:%02hhu:%02hhu %n", &hour, &minute, &second, &num) == 3 &&  // NOLINT
+             num == ilen) {
     esp_time.hour = hour;
     esp_time.minute = minute;
     esp_time.second = second;
-  } else if (sscanf(time_to_parse.c_str(), "%02hhu:%02hhu %n", &hour, &minute, &num) == 2 &&  // NOLINT
-             num == static_cast<int>(time_to_parse.size())) {
+  } else if (sscanf(time_to_parse, "%02hhu:%02hhu %n", &hour, &minute, &num) == 2 &&  // NOLINT
+             num == ilen) {
     esp_time.hour = hour;
     esp_time.minute = minute;
     esp_time.second = 0;
-  } else if (sscanf(time_to_parse.c_str(), "%04hu-%02hhu-%02hhu %n", &year, &month, &day, &num) == 3 &&  // NOLINT
-             num == static_cast<int>(time_to_parse.size())) {
+  } else if (sscanf(time_to_parse, "%04hu-%02hhu-%02hhu %n", &year, &month, &day, &num) == 3 &&  // NOLINT
+             num == ilen) {
     esp_time.year = year;
     esp_time.month = month;
     esp_time.day_of_month = day;
diff --git a/esphome/core/time.h b/esphome/core/time.h
index f6f1d57dbb..87ebb5c221 100644
--- a/esphome/core/time.h
+++ b/esphome/core/time.h
@@ -2,6 +2,7 @@
 
 #include <cstdint>
 #include <cstdlib>
+#include <cstring>
 #include <ctime>
 #include <span>
 #include <string>
@@ -80,11 +81,20 @@ struct ESPTime {
   }
 
   /** Convert a string to ESPTime struct as specified by the format argument.
-   * @param time_to_parse null-terminated c string formatet like this: 2020-08-25 05:30:00.
+   * @param time_to_parse c string formatted like this: 2020-08-25 05:30:00.
+   * @param len length of the string (not including null terminator if present)
    * @param esp_time an instance of a ESPTime struct
-   * @return the success sate of the parsing
+   * @return the success state of the parsing
    */
-  static bool strptime(const std::string &time_to_parse, ESPTime &esp_time);
+  static bool strptime(const char *time_to_parse, size_t len, ESPTime &esp_time);
+  /// @copydoc strptime(const char *, size_t, ESPTime &)
+  static bool strptime(const char *time_to_parse, ESPTime &esp_time) {
+    return strptime(time_to_parse, strlen(time_to_parse), esp_time);
+  }
+  /// @copydoc strptime(const char *, size_t, ESPTime &)
+  static bool strptime(const std::string &time_to_parse, ESPTime &esp_time) {
+    return strptime(time_to_parse.c_str(), time_to_parse.size(), esp_time);
+  }
 
   /// Convert a C tm struct instance with a C unix epoch timestamp to an ESPTime instance.
   static ESPTime from_c_tm(struct tm *c_tm, time_t c_time);
diff --git a/esphome/cpp_types.py b/esphome/cpp_types.py
index 0d1813f63b..7001c38857 100644
--- a/esphome/cpp_types.py
+++ b/esphome/cpp_types.py
@@ -44,3 +44,4 @@ gpio_Flags = gpio_ns.enum("Flags", is_class=True)
 EntityCategory = esphome_ns.enum("EntityCategory")
 Parented = esphome_ns.class_("Parented")
 ESPTime = esphome_ns.struct("ESPTime")
+StringRef = esphome_ns.class_("StringRef")
diff --git a/esphome/espidf_api.py b/esphome/espidf_api.py
new file mode 100644
index 0000000000..9e9c57bfbd
--- /dev/null
+++ b/esphome/espidf_api.py
@@ -0,0 +1,229 @@
+"""ESP-IDF direct build API for ESPHome."""
+
+import json
+import logging
+import os
+from pathlib import Path
+import shutil
+import subprocess
+
+from esphome.components.esp32.const import KEY_ESP32, KEY_FLASH_SIZE
+from esphome.const import CONF_COMPILE_PROCESS_LIMIT, CONF_ESPHOME
+from esphome.core import CORE, EsphomeError
+
+_LOGGER = logging.getLogger(__name__)
+
+
+def _get_idf_path() -> Path | None:
+    """Get IDF_PATH from environment or common locations."""
+    # Check environment variable first
+    if "IDF_PATH" in os.environ:
+        path = Path(os.environ["IDF_PATH"])
+        if path.is_dir():
+            return path
+
+    # Check common installation locations
+    common_paths = [
+        Path.home() / "esp" / "esp-idf",
+        Path.home() / ".espressif" / "esp-idf",
+        Path("/opt/esp-idf"),
+    ]
+
+    for path in common_paths:
+        if path.is_dir() and (path / "tools" / "idf.py").is_file():
+            return path
+
+    return None
+
+
+def _get_idf_env() -> dict[str, str]:
+    """Get environment variables needed for ESP-IDF build.
+
+    Requires the user to have sourced export.sh before running esphome.
+    """
+    env = os.environ.copy()
+
+    idf_path = _get_idf_path()
+    if idf_path is None:
+        raise EsphomeError(
+            "ESP-IDF not found. Please install ESP-IDF and source export.sh:\n"
+            "  git clone -b v5.3.2 --recursive https://github.com/espressif/esp-idf.git ~/esp-idf\n"
+            "  cd ~/esp-idf && ./install.sh\n"
+            "  source ~/esp-idf/export.sh\n"
+            "See: https://docs.espressif.com/projects/esp-idf/en/latest/esp32/get-started/"
+        )
+
+    env["IDF_PATH"] = str(idf_path)
+    return env
+
+
+def run_idf_py(
+    *args, cwd: Path | None = None, capture_output: bool = False
+) -> int | str:
+    """Run idf.py with the given arguments."""
+    idf_path = _get_idf_path()
+    if idf_path is None:
+        raise EsphomeError("ESP-IDF not found")
+
+    env = _get_idf_env()
+    idf_py = idf_path / "tools" / "idf.py"
+
+    cmd = ["python", str(idf_py)] + list(args)
+
+    if cwd is None:
+        cwd = CORE.build_path
+
+    _LOGGER.debug("Running: %s", " ".join(cmd))
+    _LOGGER.debug("  in directory: %s", cwd)
+
+    if capture_output:
+        result = subprocess.run(
+            cmd,
+            cwd=cwd,
+            env=env,
+            capture_output=True,
+            text=True,
+            check=False,
+        )
+        if result.returncode != 0:
+            _LOGGER.error("idf.py failed:\n%s", result.stderr)
+        return result.stdout
+    result = subprocess.run(
+        cmd,
+        cwd=cwd,
+        env=env,
+        check=False,
+    )
+    return result.returncode
+
+
+def run_reconfigure() -> int:
+    """Run cmake reconfigure only (no build)."""
+    return run_idf_py("reconfigure")
+
+
+def run_compile(config, verbose: bool) -> int:
+    """Compile the ESP-IDF project.
+
+    Uses two-phase configure to auto-discover available components:
+    1. If no previous build, configure with minimal REQUIRES to discover components
+    2. Regenerate CMakeLists.txt with discovered components
+    3. Run full build
+    """
+    from esphome.build_gen.espidf import has_discovered_components, write_project
+
+    # Check if we need to do discovery phase
+    if not has_discovered_components():
+        _LOGGER.info("Discovering available ESP-IDF components...")
+        write_project(minimal=True)
+        rc = run_reconfigure()
+        if rc != 0:
+            _LOGGER.error("Component discovery failed")
+            return rc
+        _LOGGER.info("Regenerating CMakeLists.txt with discovered components...")
+        write_project(minimal=False)
+
+    # Build
+    args = ["build"]
+
+    if verbose:
+        args.append("-v")
+
+    # Add parallel job limit if configured
+    if CONF_COMPILE_PROCESS_LIMIT in config.get(CONF_ESPHOME, {}):
+        limit = config[CONF_ESPHOME][CONF_COMPILE_PROCESS_LIMIT]
+        args.extend(["-j", str(limit)])
+
+    # Set the sdkconfig file
+    sdkconfig_path = CORE.relative_build_path(f"sdkconfig.{CORE.name}")
+    if sdkconfig_path.is_file():
+        args.extend(["-D", f"SDKCONFIG={sdkconfig_path}"])
+
+    return run_idf_py(*args)
+
+
+def get_firmware_path() -> Path:
+    """Get the path to the compiled firmware binary."""
+    build_dir = CORE.relative_build_path("build")
+    return build_dir / f"{CORE.name}.bin"
+
+
+def get_factory_firmware_path() -> Path:
+    """Get the path to the factory firmware (with bootloader)."""
+    build_dir = CORE.relative_build_path("build")
+    return build_dir / f"{CORE.name}.factory.bin"
+
+
+def create_factory_bin() -> bool:
+    """Create factory.bin by merging bootloader, partition table, and app."""
+    build_dir = CORE.relative_build_path("build")
+    flasher_args_path = build_dir / "flasher_args.json"
+
+    if not flasher_args_path.is_file():
+        _LOGGER.warning("flasher_args.json not found, cannot create factory.bin")
+        return False
+
+    try:
+        with open(flasher_args_path, encoding="utf-8") as f:
+            flash_data = json.load(f)
+    except (json.JSONDecodeError, OSError) as e:
+        _LOGGER.error("Failed to read flasher_args.json: %s", e)
+        return False
+
+    # Get flash size from config
+    flash_size = CORE.data[KEY_ESP32][KEY_FLASH_SIZE]
+
+    # Build esptool merge command
+    sections = []
+    for addr, fname in sorted(
+        flash_data.get("flash_files", {}).items(), key=lambda kv: int(kv[0], 16)
+    ):
+        file_path = build_dir / fname
+        if file_path.is_file():
+            sections.extend([addr, str(file_path)])
+        else:
+            _LOGGER.warning("Flash file not found: %s", file_path)
+
+    if not sections:
+        _LOGGER.warning("No flash sections found")
+        return False
+
+    output_path = get_factory_firmware_path()
+    chip = flash_data.get("extra_esptool_args", {}).get("chip", "esp32")
+
+    cmd = [
+        "python",
+        "-m",
+        "esptool",
+        "--chip",
+        chip,
+        "merge_bin",
+        "--flash_size",
+        flash_size,
+        "--output",
+        str(output_path),
+    ] + sections
+
+    _LOGGER.info("Creating factory.bin...")
+    result = subprocess.run(cmd, capture_output=True, text=True, check=False)
+
+    if result.returncode != 0:
+        _LOGGER.error("Failed to create factory.bin: %s", result.stderr)
+        return False
+
+    _LOGGER.info("Created: %s", output_path)
+    return True
+
+
+def create_ota_bin() -> bool:
+    """Copy the firmware to .ota.bin for ESPHome OTA compatibility."""
+    firmware_path = get_firmware_path()
+    ota_path = firmware_path.with_suffix(".ota.bin")
+
+    if not firmware_path.is_file():
+        _LOGGER.warning("Firmware not found: %s", firmware_path)
+        return False
+
+    shutil.copy(firmware_path, ota_path)
+    _LOGGER.info("Created: %s", ota_path)
+    return True
diff --git a/esphome/idf_component.yml b/esphome/idf_component.yml
index 045b3f9168..9be787d0cd 100644
--- a/esphome/idf_component.yml
+++ b/esphome/idf_component.yml
@@ -1,4 +1,8 @@
 dependencies:
+  bblanchon/arduinojson:
+    version: "7.4.2"
+  esphome/esp-audio-libs:
+    version: 2.0.3
   espressif/esp-tflite-micro:
     version: 1.3.3~1
   espressif/esp32-camera:
@@ -28,8 +32,8 @@ dependencies:
     rules:
       - if: "target in [esp32s2, esp32s3, esp32p4]"
   esphome/esp-hub75:
-    version: 0.2.2
+    version: 0.3.0
     rules:
-      - if: "target in [esp32, esp32s2, esp32s3, esp32p4]"
+      - if: "target in [esp32, esp32s2, esp32s3, esp32c6, esp32p4]"
   esp32async/asynctcp:
     version: 3.4.91
diff --git a/platformio.ini b/platformio.ini
index 4180971b54..e9a588e4fd 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -34,7 +34,6 @@ build_flags =
 [common]
 ; Base dependencies for all environments
 lib_deps_base =
-    bblanchon/ArduinoJson@7.4.2            ; json
     wjtje/qr-code-generator-library@1.7.0  ; qr_code
     functionpointer/arduino-MLX90393@1.0.2 ; mlx90393
     pavlodn/HaierProtocol@0.9.31           ; haier
@@ -85,7 +84,7 @@ lib_deps =
     fastled/FastLED@3.9.16                                ; fastled_base
     freekode/TM1651@1.0.1                                 ; tm1651
     dudanov/MideaUART@1.1.9                               ; midea
-    tonia/HeatpumpIR@1.0.37                               ; heatpumpir
+    tonia/HeatpumpIR@1.0.40                               ; heatpumpir
 build_flags =
     ${common.build_flags}
     -DUSE_ARDUINO
@@ -111,6 +110,7 @@ platform_packages =
 framework = arduino
 lib_deps =
     ${common:arduino.lib_deps}
+    bblanchon/ArduinoJson@7.4.2           ; json
     ESP8266WiFi                           ; wifi (Arduino built-in)
     Update                                ; ota (Arduino built-in)
     ESP32Async/ESPAsyncTCP@2.0.0          ; async_tcp
@@ -133,9 +133,9 @@ extra_scripts = post:esphome/components/esp8266/post_build.py.script
 ; This are common settings for the ESP32 (all variants) using Arduino.
 [common:esp32-arduino]
 extends = common:arduino
-platform = https://github.com/pioarduino/platform-espressif32/releases/download/55.03.35/platform-espressif32.zip
+platform = https://github.com/pioarduino/platform-espressif32/releases/download/55.03.36/platform-espressif32.zip
 platform_packages =
-    pioarduino/framework-arduinoespressif32@https://github.com/espressif/arduino-esp32/releases/download/3.3.5/esp32-3.3.5.zip
+    pioarduino/framework-arduinoespressif32@https://github.com/espressif/arduino-esp32/releases/download/3.3.6/esp32-core-3.3.6.tar.xz
 
 framework = arduino, espidf  ; Arduino as an ESP-IDF component
 lib_deps =
@@ -154,7 +154,6 @@ lib_deps =
     makuna/NeoPixelBus@2.8.0             ; neopixelbus
     esphome/ESP32-audioI2S@2.3.0         ; i2s_audio
     droscy/esp_wireguard@0.4.2           ; wireguard
-    esphome/esp-audio-libs@2.0.1         ; audio
     kahrendt/ESPMicroSpeechFeatures@1.1.0  ; micro_wake_word
 
 build_flags =
@@ -169,7 +168,7 @@ extra_scripts = post:esphome/components/esp32/post_build.py.script
 ; This are common settings for the ESP32 (all variants) using IDF.
 [common:esp32-idf]
 extends = common:idf
-platform = https://github.com/pioarduino/platform-espressif32/releases/download/55.03.35/platform-espressif32.zip
+platform = https://github.com/pioarduino/platform-espressif32/releases/download/55.03.36/platform-espressif32.zip
 platform_packages =
     pioarduino/framework-espidf@https://github.com/pioarduino/esp-idf/releases/download/v5.5.2/esp-idf-v5.5.2.tar.xz
 
@@ -178,7 +177,7 @@ lib_deps =
     ${common:idf.lib_deps}
     droscy/esp_wireguard@0.4.2              ; wireguard
     kahrendt/ESPMicroSpeechFeatures@1.1.0   ; micro_wake_word
-    esphome/esp-audio-libs@2.0.1            ; audio
+    tonia/HeatpumpIR@1.0.40                 ; heatpumpir
 build_flags =
     ${common:idf.build_flags}
     -Wno-nonnull-compare
@@ -201,6 +200,7 @@ platform_packages =
 framework = arduino
 lib_deps =
     ${common:arduino.lib_deps}
+    bblanchon/ArduinoJson@7.4.2           ; json
     ESP32Async/ESPAsyncWebServer@3.7.8    ; web_server_base
 build_flags =
     ${common:arduino.build_flags}
@@ -216,6 +216,7 @@ platform = libretiny@1.9.2
 framework = arduino
 lib_compat_mode = soft
 lib_deps =
+    bblanchon/ArduinoJson@7.4.2           ; json
     ESP32Async/ESPAsyncWebServer@3.7.8    ; web_server_base
     droscy/esp_wireguard@0.4.2            ; wireguard
 build_flags =
@@ -239,6 +240,7 @@ build_flags =
     -DUSE_NRF52
 lib_deps =
     ${common.lib_deps_base}
+    bblanchon/ArduinoJson@7.4.2           ; json
 
 ; All the actual environments are defined below.
 
diff --git a/pyproject.toml b/pyproject.toml
index d6aa584237..47dd4b7473 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,5 +1,5 @@
 [build-system]
-requires = ["setuptools==80.9.0", "wheel>=0.43,<0.46"]
+requires = ["setuptools==80.10.1", "wheel>=0.43,<0.46"]
 build-backend = "setuptools.build_meta"
 
 [project]
diff --git a/script/ci-custom.py b/script/ci-custom.py
index e63e61e096..01e197057a 100755
--- a/script/ci-custom.py
+++ b/script/ci-custom.py
@@ -682,11 +682,13 @@ def lint_trailing_whitespace(fname, match):
 # Heap-allocating helpers that cause fragmentation on long-running embedded devices.
 # These return std::string and should be replaced with stack-based alternatives.
 HEAP_ALLOCATING_HELPERS = {
+    "format_bin": "format_bin_to() with a stack buffer",
     "format_hex": "format_hex_to() with a stack buffer",
     "format_hex_pretty": "format_hex_pretty_to() with a stack buffer",
     "format_mac_address_pretty": "format_mac_addr_upper() with a stack buffer",
     "get_mac_address": "get_mac_address_into_buffer() with a stack buffer",
     "get_mac_address_pretty": "get_mac_address_pretty_into_buffer() with a stack buffer",
+    "str_sanitize": "str_sanitize_to() with a stack buffer",
     "str_truncate": "removal (function is unused)",
     "str_upper_case": "removal (function is unused)",
     "str_snake_case": "removal (function is unused)",
@@ -699,11 +701,13 @@ HEAP_ALLOCATING_HELPERS = {
     # get_mac_address(?!_) ensures we don't match get_mac_address_into_buffer, etc.
     # CPP_RE_EOL captures rest of line so NOLINT comments are detected
     r"[^\w]("
+    r"format_bin(?!_)|"
     r"format_hex(?!_)|"
     r"format_hex_pretty(?!_)|"
     r"format_mac_address_pretty|"
     r"get_mac_address_pretty(?!_)|"
     r"get_mac_address(?!_)|"
+    r"str_sanitize(?!_)|"
     r"str_truncate|"
     r"str_upper_case|"
     r"str_snake_case"
@@ -728,6 +732,26 @@ def lint_no_heap_allocating_helpers(fname, match):
     )
 
 
+@lint_re_check(
+    # Match sprintf/vsprintf but not snprintf/vsnprintf
+    # [^\w] ensures we don't match the safe variants
+    r"[^\w](v?sprintf)\s*\(" + CPP_RE_EOL,
+    include=cpp_include,
+)
+def lint_no_sprintf(fname, match):
+    func = match.group(1)
+    safe_func = func.replace("sprintf", "snprintf")
+    return (
+        f"{highlight(func + '()')} is not allowed in ESPHome. It has no buffer size limit "
+        f"and can cause buffer overflows.\n"
+        f"Please use one of these alternatives:\n"
+        f"  - {highlight(safe_func + '(buf, sizeof(buf), fmt, ...)')} for general formatting\n"
+        f"  - {highlight('buf_append_printf(buf, sizeof(buf), pos, fmt, ...)')} for "
+        f"offset-based formatting (also stores format strings in flash on ESP8266)\n"
+        f"(If strictly necessary, add `// NOLINT` to the end of the line)"
+    )
+
+
 @lint_content_find_check(
     "ESP_LOG",
     include=["*.h", "*.tcc"],
diff --git a/tests/components/alarm_control_panel/common.yaml b/tests/components/alarm_control_panel/common.yaml
index 142bf3c7e6..39d5739255 100644
--- a/tests/components/alarm_control_panel/common.yaml
+++ b/tests/components/alarm_control_panel/common.yaml
@@ -9,6 +9,8 @@ alarm_control_panel:
     name: Alarm Panel
     codes:
       - "1234"
+      - "5678"
+      - "0000"
     requires_code_to_arm: true
     arming_home_time: 1s
     arming_night_time: 1s
@@ -29,6 +31,7 @@ alarm_control_panel:
     name: Alarm Panel 2
     codes:
       - "1234"
+      - "9999"
     requires_code_to_arm: true
     arming_home_time: 1s
     arming_night_time: 1s
diff --git a/tests/components/debug/test.nrf52-adafruit.yaml b/tests/components/debug/test.nrf52-adafruit.yaml
index dade44d145..6a446634af 100644
--- a/tests/components/debug/test.nrf52-adafruit.yaml
+++ b/tests/components/debug/test.nrf52-adafruit.yaml
@@ -1 +1,5 @@
 <<: !include common.yaml
+
+nrf52:
+  reg0:
+    voltage: 2.1V
diff --git a/tests/components/heatpumpir/test.esp32-idf.yaml b/tests/components/heatpumpir/test.esp32-idf.yaml
new file mode 100644
index 0000000000..e891f9dc85
--- /dev/null
+++ b/tests/components/heatpumpir/test.esp32-idf.yaml
@@ -0,0 +1,4 @@
+packages:
+  remote_transmitter: !include ../../test_build_components/common/remote_transmitter/esp32-idf.yaml
+
+<<: !include common.yaml
diff --git a/tests/components/nextion/common.yaml b/tests/components/nextion/common.yaml
index f5ee12a51c..48a7292f43 100644
--- a/tests/components/nextion/common.yaml
+++ b/tests/components/nextion/common.yaml
@@ -277,6 +277,8 @@ display:
     command_spacing: 5ms
     max_commands_per_loop: 20
     max_queue_size: 50
+    startup_override_ms: 10000ms  # Wait 10s for display ready
+    max_queue_age: 5000ms         # Remove queue items after 5s
     on_sleep:
       then:
         lambda: 'ESP_LOGD("display","Display went to sleep");'
diff --git a/tests/components/template/common-base.yaml b/tests/components/template/common-base.yaml
index 3b888c3d19..afc3fd9819 100644
--- a/tests/components/template/common-base.yaml
+++ b/tests/components/template/common-base.yaml
@@ -121,6 +121,8 @@ sensor:
           min_value: -10.0
       - debounce: 0.1s
       - delta: 5.0
+      - delta:
+          max_value: 2%
       - exponential_moving_average:
           alpha: 0.1
           send_every: 15
diff --git a/tests/components/udp/common.yaml b/tests/components/udp/common.yaml
index 98546d49ef..3466e8d2ee 100644
--- a/tests/components/udp/common.yaml
+++ b/tests/components/udp/common.yaml
@@ -5,7 +5,10 @@ wifi:
 udp:
   id: my_udp
   listen_address: 239.0.60.53
-  addresses: ["239.0.60.53"]
+  addresses:
+    - "239.0.60.53"
+    - "192.168.1.255"
+    - "10.0.0.255"
   on_receive:
     - logger.log:
         format: "Received %d bytes"
diff --git a/tests/integration/fixtures/api_homeassistant.yaml b/tests/integration/fixtures/api_homeassistant.yaml
index 8fe23b9a19..2d77821ff3 100644
--- a/tests/integration/fixtures/api_homeassistant.yaml
+++ b/tests/integration/fixtures/api_homeassistant.yaml
@@ -108,6 +108,25 @@ text_sensor:
             format: "HA Empty state updated: %s"
             args: ['x.c_str()']
 
+  # Test long attribute handling (>255 characters)
+  # HA states are limited to 255 chars, but attributes are not
+  - platform: homeassistant
+    name: "HA Long Attribute"
+    entity_id: sensor.long_data
+    attribute: long_value
+    id: ha_long_attribute
+    on_value:
+      then:
+        - logger.log:
+            format: "HA Long attribute received, length: %d"
+            args: ['x.size()']
+        # Log the first 50 and last 50 chars to verify no truncation
+        - lambda: |-
+            if (x.size() >= 100) {
+              ESP_LOGI("test", "Long attribute first 50 chars: %.50s", x.c_str());
+              ESP_LOGI("test", "Long attribute last 50 chars: %s", x.c_str() + x.size() - 50);
+            }
+
 # Number component for testing HA number control
 number:
   - platform: template
diff --git a/tests/integration/fixtures/select_stringref_trigger.yaml b/tests/integration/fixtures/select_stringref_trigger.yaml
new file mode 100644
index 0000000000..bb1e1fd843
--- /dev/null
+++ b/tests/integration/fixtures/select_stringref_trigger.yaml
@@ -0,0 +1,85 @@
+esphome:
+  name: select-stringref-test
+  friendly_name: Select StringRef Test
+
+host:
+
+logger:
+  level: DEBUG
+
+api:
+
+select:
+  - platform: template
+    name: "Test Select"
+    id: test_select
+    optimistic: true
+    options:
+      - "Option A"
+      - "Option B"
+      - "Option C"
+    initial_option: "Option A"
+    on_value:
+      then:
+        # Test 1: Log the value directly (StringRef -> const char* via c_str())
+        - logger.log:
+            format: "Select value: %s"
+            args: ['x.c_str()']
+        # Test 2: String concatenation (StringRef + const char* -> std::string)
+        - lambda: |-
+            std::string with_suffix = x + " selected";
+            ESP_LOGI("test", "Concatenated: %s", with_suffix.c_str());
+        # Test 3: Comparison (StringRef == const char*)
+        - lambda: |-
+            if (x == "Option B") {
+              ESP_LOGI("test", "Option B was selected");
+            }
+        # Test 4: Use index parameter (variable name is 'i')
+        - lambda: |-
+            ESP_LOGI("test", "Select index: %d", (int)i);
+        # Test 5: StringRef.length() method
+        - lambda: |-
+            ESP_LOGI("test", "Length: %d", (int)x.length());
+        # Test 6: StringRef.find() method with substring
+        - lambda: |-
+            if (x.find("Option") != std::string::npos) {
+              ESP_LOGI("test", "Found 'Option' in value");
+            }
+        # Test 7: StringRef.find() method with character
+        - lambda: |-
+            size_t space_pos = x.find(' ');
+            if (space_pos != std::string::npos) {
+              ESP_LOGI("test", "Space at position: %d", (int)space_pos);
+            }
+        # Test 8: StringRef.substr() method
+        - lambda: |-
+            std::string prefix = x.substr(0, 6);
+            ESP_LOGI("test", "Substr prefix: %s", prefix.c_str());
+
+  # Second select with numeric options to test ADL functions
+  - platform: template
+    name: "Baud Rate"
+    id: baud_select
+    optimistic: true
+    options:
+      - "9600"
+      - "115200"
+    initial_option: "9600"
+    on_value:
+      then:
+        # Test 9: stoi via ADL
+        - lambda: |-
+            int baud = stoi(x);
+            ESP_LOGI("test", "stoi result: %d", baud);
+        # Test 10: stol via ADL
+        - lambda: |-
+            long baud_long = stol(x);
+            ESP_LOGI("test", "stol result: %ld", baud_long);
+        # Test 11: stof via ADL
+        - lambda: |-
+            float baud_float = stof(x);
+            ESP_LOGI("test", "stof result: %.0f", baud_float);
+        # Test 12: stod via ADL
+        - lambda: |-
+            double baud_double = stod(x);
+            ESP_LOGI("test", "stod result: %.0f", baud_double);
diff --git a/tests/integration/fixtures/sensor_filters_delta.yaml b/tests/integration/fixtures/sensor_filters_delta.yaml
new file mode 100644
index 0000000000..19bd2d5ca4
--- /dev/null
+++ b/tests/integration/fixtures/sensor_filters_delta.yaml
@@ -0,0 +1,180 @@
+esphome:
+  name: test-delta-filters
+
+host:
+api:
+  batch_delay: 0ms  # Disable batching to receive all state updates
+logger:
+  level: DEBUG
+
+sensor:
+  - platform: template
+    name: "Source Sensor 1"
+    id: source_sensor_1
+    accuracy_decimals: 1
+
+  - platform: template
+    name: "Source Sensor 2"
+    id: source_sensor_2
+    accuracy_decimals: 1
+
+  - platform: template
+    name: "Source Sensor 3"
+    id: source_sensor_3
+    accuracy_decimals: 1
+
+  - platform: template
+    name: "Source Sensor 4"
+    id: source_sensor_4
+    accuracy_decimals: 1
+
+  - platform: copy
+    source_id: source_sensor_1
+    name: "Filter Min"
+    id: filter_min
+    filters:
+      - delta:
+          min_value: 10
+
+  - platform: copy
+    source_id: source_sensor_2
+    name: "Filter Max"
+    id: filter_max
+    filters:
+      - delta:
+          max_value: 10
+
+  - platform: copy
+    source_id: source_sensor_3
+    id: test_3_baseline
+    filters:
+      - median:
+          window_size: 6
+          send_every: 1
+          send_first_at: 1
+
+  - platform: copy
+    source_id: source_sensor_3
+    name: "Filter Baseline Max"
+    id: filter_baseline_max
+    filters:
+      - delta:
+          max_value: 10
+          baseline: !lambda return id(test_3_baseline).state;
+
+  - platform: copy
+    source_id: source_sensor_4
+    name: "Filter Zero Delta"
+    id: filter_zero_delta
+    filters:
+      - delta: 0
+
+script:
+  - id: test_filter_min
+    then:
+      - sensor.template.publish:
+          id: source_sensor_1
+          state: 1.0
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_1
+          state: 5.0  # Filtered out
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_1
+          state: 12.0
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_1
+          state: 8.0  # Filtered out
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_1
+          state: -2.0
+
+  - id: test_filter_max
+    then:
+      - sensor.template.publish:
+          id: source_sensor_2
+          state: 1.0
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_2
+          state: 5.0
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_2
+          state: 40.0  # Filtered out
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_2
+          state: 10.0
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_2
+          state: -40.0  # Filtered out
+
+  - id: test_filter_baseline_max
+    then:
+      - sensor.template.publish:
+          id: source_sensor_3
+          state: 1.0
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_3
+          state: 2.0
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_3
+          state: 3.0
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_3
+          state: 40.0  # Filtered out
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_3
+          state: 20.0  # Filtered out
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_3
+          state: 20.0
+
+  - id: test_filter_zero_delta
+    then:
+      - sensor.template.publish:
+          id: source_sensor_4
+          state: 1.0
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_4
+          state: 1.0  # Filtered out
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_4
+          state: 2.0
+
+button:
+  - platform: template
+    name: "Test Filter Min"
+    id: btn_filter_min
+    on_press:
+      - script.execute: test_filter_min
+
+  - platform: template
+    name: "Test Filter Max"
+    id: btn_filter_max
+    on_press:
+      - script.execute: test_filter_max
+
+  - platform: template
+    name: "Test Filter Baseline Max"
+    id: btn_filter_baseline_max
+    on_press:
+      - script.execute: test_filter_baseline_max
+
+  - platform: template
+    name: "Test Filter Zero Delta"
+    id: btn_filter_zero_delta
+    on_press:
+      - script.execute: test_filter_zero_delta
diff --git a/tests/integration/fixtures/udp_send_receive.yaml b/tests/integration/fixtures/udp_send_receive.yaml
new file mode 100644
index 0000000000..155d932722
--- /dev/null
+++ b/tests/integration/fixtures/udp_send_receive.yaml
@@ -0,0 +1,33 @@
+esphome:
+  name: udp-test
+
+host:
+
+api:
+  services:
+    - service: send_udp_message
+      then:
+        - udp.write:
+            id: test_udp
+            data: "HELLO_UDP_TEST"
+    - service: send_udp_bytes
+      then:
+        - udp.write:
+            id: test_udp
+            data: [0x55, 0x44, 0x50, 0x5F, 0x42, 0x59, 0x54, 0x45, 0x53]  # "UDP_BYTES"
+
+logger:
+  level: DEBUG
+
+udp:
+  - id: test_udp
+    addresses:
+      - "127.0.0.1"
+      - "127.0.0.2"
+    port:
+      listen_port: UDP_LISTEN_PORT_PLACEHOLDER
+      broadcast_port: UDP_BROADCAST_PORT_PLACEHOLDER
+    on_receive:
+      - logger.log:
+          format: "Received UDP: %d bytes"
+          args: [data.size()]
diff --git a/tests/integration/test_api_homeassistant.py b/tests/integration/test_api_homeassistant.py
index 3fe0dfe045..b4adedf873 100644
--- a/tests/integration/test_api_homeassistant.py
+++ b/tests/integration/test_api_homeassistant.py
@@ -40,6 +40,7 @@ async def test_api_homeassistant(
     humidity_update_future = loop.create_future()
     motion_update_future = loop.create_future()
     weather_update_future = loop.create_future()
+    long_attr_future = loop.create_future()
 
     # Number future
     ha_number_future = loop.create_future()
@@ -58,6 +59,7 @@ async def test_api_homeassistant(
     humidity_update_pattern = re.compile(r"HA Humidity state updated: ([\d.]+)")
     motion_update_pattern = re.compile(r"HA Motion state changed: (ON|OFF)")
     weather_update_pattern = re.compile(r"HA Weather condition updated: (\w+)")
+    long_attr_pattern = re.compile(r"HA Long attribute received, length: (\d+)")
 
     # Number pattern
     ha_number_pattern = re.compile(r"Setting HA number to: ([\d.]+)")
@@ -143,8 +145,14 @@ async def test_api_homeassistant(
         elif not weather_update_future.done() and weather_update_pattern.search(line):
             weather_update_future.set_result(line)
 
-        # Check number pattern
-        elif not ha_number_future.done() and ha_number_pattern.search(line):
+        # Check long attribute pattern - separate if since it can come at different times
+        if not long_attr_future.done():
+            match = long_attr_pattern.search(line)
+            if match:
+                long_attr_future.set_result(int(match.group(1)))
+
+        # Check number pattern - separate if since it can come at different times
+        if not ha_number_future.done():
             match = ha_number_pattern.search(line)
             if match:
                 ha_number_future.set_result(match.group(1))
@@ -179,6 +187,14 @@ async def test_api_homeassistant(
         client.send_home_assistant_state("binary_sensor.external_motion", "", "ON")
         client.send_home_assistant_state("weather.home", "condition", "sunny")
 
+        # Send a long attribute (300 characters) to test that attributes aren't truncated
+        # HA states are limited to 255 chars, but attributes are NOT limited
+        # This tests the fix for the 256-byte buffer truncation bug
+        long_attr_value = "X" * 300  # 300 chars - enough to expose truncation bug
+        client.send_home_assistant_state(
+            "sensor.long_data", "long_value", long_attr_value
+        )
+
         # Test edge cases for zero-copy implementation safety
         # Empty entity_id should be silently ignored (no crash)
         client.send_home_assistant_state("", "", "should_be_ignored")
@@ -225,6 +241,13 @@ async def test_api_homeassistant(
             number_value = await asyncio.wait_for(ha_number_future, timeout=5.0)
             assert number_value == "42.5", f"Unexpected number value: {number_value}"
 
+            # Long attribute test - verify 300 chars weren't truncated to 255
+            long_attr_len = await asyncio.wait_for(long_attr_future, timeout=5.0)
+            assert long_attr_len == 300, (
+                f"Long attribute was truncated! Expected 300 chars, got {long_attr_len}. "
+                "This indicates the 256-byte truncation bug."
+            )
+
             # Wait for completion
             await asyncio.wait_for(tests_complete_future, timeout=5.0)
 
diff --git a/tests/integration/test_select_stringref_trigger.py b/tests/integration/test_select_stringref_trigger.py
new file mode 100644
index 0000000000..7fc72a2290
--- /dev/null
+++ b/tests/integration/test_select_stringref_trigger.py
@@ -0,0 +1,143 @@
+"""Integration test for select on_value trigger with StringRef parameter."""
+
+from __future__ import annotations
+
+import asyncio
+import re
+
+import pytest
+
+from .types import APIClientConnectedFactory, RunCompiledFunction
+
+
+@pytest.mark.asyncio
+async def test_select_stringref_trigger(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    """Test select on_value trigger passes StringRef that works with string operations."""
+    loop = asyncio.get_running_loop()
+
+    # Track log messages to verify StringRef operations work
+    value_logged_future = loop.create_future()
+    concatenated_future = loop.create_future()
+    comparison_future = loop.create_future()
+    index_logged_future = loop.create_future()
+    length_future = loop.create_future()
+    find_substr_future = loop.create_future()
+    find_char_future = loop.create_future()
+    substr_future = loop.create_future()
+    # ADL functions
+    stoi_future = loop.create_future()
+    stol_future = loop.create_future()
+    stof_future = loop.create_future()
+    stod_future = loop.create_future()
+
+    # Patterns to match in logs
+    value_pattern = re.compile(r"Select value: Option B")
+    concatenated_pattern = re.compile(r"Concatenated: Option B selected")
+    comparison_pattern = re.compile(r"Option B was selected")
+    index_pattern = re.compile(r"Select index: 1")
+    length_pattern = re.compile(r"Length: 8")  # "Option B" is 8 chars
+    find_substr_pattern = re.compile(r"Found 'Option' in value")
+    find_char_pattern = re.compile(r"Space at position: 6")  # space at index 6
+    substr_pattern = re.compile(r"Substr prefix: Option")
+    # ADL function patterns (115200 from baud rate select)
+    stoi_pattern = re.compile(r"stoi result: 115200")
+    stol_pattern = re.compile(r"stol result: 115200")
+    stof_pattern = re.compile(r"stof result: 115200")
+    stod_pattern = re.compile(r"stod result: 115200")
+
+    def check_output(line: str) -> None:
+        """Check log output for expected messages."""
+        if not value_logged_future.done() and value_pattern.search(line):
+            value_logged_future.set_result(True)
+        if not concatenated_future.done() and concatenated_pattern.search(line):
+            concatenated_future.set_result(True)
+        if not comparison_future.done() and comparison_pattern.search(line):
+            comparison_future.set_result(True)
+        if not index_logged_future.done() and index_pattern.search(line):
+            index_logged_future.set_result(True)
+        if not length_future.done() and length_pattern.search(line):
+            length_future.set_result(True)
+        if not find_substr_future.done() and find_substr_pattern.search(line):
+            find_substr_future.set_result(True)
+        if not find_char_future.done() and find_char_pattern.search(line):
+            find_char_future.set_result(True)
+        if not substr_future.done() and substr_pattern.search(line):
+            substr_future.set_result(True)
+        # ADL functions
+        if not stoi_future.done() and stoi_pattern.search(line):
+            stoi_future.set_result(True)
+        if not stol_future.done() and stol_pattern.search(line):
+            stol_future.set_result(True)
+        if not stof_future.done() and stof_pattern.search(line):
+            stof_future.set_result(True)
+        if not stod_future.done() and stod_pattern.search(line):
+            stod_future.set_result(True)
+
+    async with (
+        run_compiled(yaml_config, line_callback=check_output),
+        api_client_connected() as client,
+    ):
+        # Verify device info
+        device_info = await client.device_info()
+        assert device_info is not None
+        assert device_info.name == "select-stringref-test"
+
+        # List entities to find our select
+        entities, _ = await client.list_entities_services()
+
+        select_entity = next(
+            (e for e in entities if hasattr(e, "options") and e.name == "Test Select"),
+            None,
+        )
+        assert select_entity is not None, "Test Select entity not found"
+
+        baud_entity = next(
+            (e for e in entities if hasattr(e, "options") and e.name == "Baud Rate"),
+            None,
+        )
+        assert baud_entity is not None, "Baud Rate entity not found"
+
+        # Change select to Option B - this should trigger on_value with StringRef
+        client.select_command(select_entity.key, "Option B")
+        # Change baud to 115200 - this tests ADL functions (stoi, stol, stof, stod)
+        client.select_command(baud_entity.key, "115200")
+
+        # Wait for all log messages confirming StringRef operations work
+        try:
+            await asyncio.wait_for(
+                asyncio.gather(
+                    value_logged_future,
+                    concatenated_future,
+                    comparison_future,
+                    index_logged_future,
+                    length_future,
+                    find_substr_future,
+                    find_char_future,
+                    substr_future,
+                    stoi_future,
+                    stol_future,
+                    stof_future,
+                    stod_future,
+                ),
+                timeout=5.0,
+            )
+        except TimeoutError:
+            results = {
+                "value_logged": value_logged_future.done(),
+                "concatenated": concatenated_future.done(),
+                "comparison": comparison_future.done(),
+                "index_logged": index_logged_future.done(),
+                "length": length_future.done(),
+                "find_substr": find_substr_future.done(),
+                "find_char": find_char_future.done(),
+                "substr": substr_future.done(),
+                "stoi": stoi_future.done(),
+                "stol": stol_future.done(),
+                "stof": stof_future.done(),
+                "stod": stod_future.done(),
+            }
+            pytest.fail(f"StringRef operations failed - received: {results}")
diff --git a/tests/integration/test_sensor_filters_delta.py b/tests/integration/test_sensor_filters_delta.py
new file mode 100644
index 0000000000..c7a26bf9d1
--- /dev/null
+++ b/tests/integration/test_sensor_filters_delta.py
@@ -0,0 +1,163 @@
+"""Test sensor DeltaFilter functionality."""
+
+from __future__ import annotations
+
+import asyncio
+
+from aioesphomeapi import ButtonInfo, EntityState, SensorState
+import pytest
+
+from .state_utils import InitialStateHelper, build_key_to_entity_mapping
+from .types import APIClientConnectedFactory, RunCompiledFunction
+
+
+@pytest.mark.asyncio
+async def test_sensor_filters_delta(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    loop = asyncio.get_running_loop()
+
+    sensor_values: dict[str, list[float]] = {
+        "filter_min": [],
+        "filter_max": [],
+        "filter_baseline_max": [],
+        "filter_zero_delta": [],
+    }
+
+    filter_min_done = loop.create_future()
+    filter_max_done = loop.create_future()
+    filter_baseline_max_done = loop.create_future()
+    filter_zero_delta_done = loop.create_future()
+
+    def on_state(state: EntityState) -> None:
+        if not isinstance(state, SensorState) or state.missing_state:
+            return
+
+        sensor_name = key_to_sensor.get(state.key)
+        if sensor_name not in sensor_values:
+            return
+
+        sensor_values[sensor_name].append(state.state)
+
+        # Check completion conditions
+        if (
+            sensor_name == "filter_min"
+            and len(sensor_values[sensor_name]) == 3
+            and not filter_min_done.done()
+        ):
+            filter_min_done.set_result(True)
+        elif (
+            sensor_name == "filter_max"
+            and len(sensor_values[sensor_name]) == 3
+            and not filter_max_done.done()
+        ):
+            filter_max_done.set_result(True)
+        elif (
+            sensor_name == "filter_baseline_max"
+            and len(sensor_values[sensor_name]) == 4
+            and not filter_baseline_max_done.done()
+        ):
+            filter_baseline_max_done.set_result(True)
+        elif (
+            sensor_name == "filter_zero_delta"
+            and len(sensor_values[sensor_name]) == 2
+            and not filter_zero_delta_done.done()
+        ):
+            filter_zero_delta_done.set_result(True)
+
+    async with (
+        run_compiled(yaml_config),
+        api_client_connected() as client,
+    ):
+        # Get entities and build key mapping
+        entities, _ = await client.list_entities_services()
+        key_to_sensor = build_key_to_entity_mapping(
+            entities,
+            {
+                "filter_min": "Filter Min",
+                "filter_max": "Filter Max",
+                "filter_baseline_max": "Filter Baseline Max",
+                "filter_zero_delta": "Filter Zero Delta",
+            },
+        )
+
+        # Set up initial state helper with all entities
+        initial_state_helper = InitialStateHelper(entities)
+
+        # Subscribe to state changes with wrapper
+        client.subscribe_states(initial_state_helper.on_state_wrapper(on_state))
+
+        # Wait for initial states
+        await initial_state_helper.wait_for_initial_states()
+
+        # Find all buttons
+        button_name_map = {
+            "Test Filter Min": "filter_min",
+            "Test Filter Max": "filter_max",
+            "Test Filter Baseline Max": "filter_baseline_max",
+            "Test Filter Zero Delta": "filter_zero_delta",
+        }
+        buttons = {}
+        for entity in entities:
+            if isinstance(entity, ButtonInfo) and entity.name in button_name_map:
+                buttons[button_name_map[entity.name]] = entity.key
+
+        assert len(buttons) == 4, f"Expected 3 buttons, found {len(buttons)}"
+
+        # Test 1: Min
+        sensor_values["filter_min"].clear()
+        client.button_command(buttons["filter_min"])
+        try:
+            await asyncio.wait_for(filter_min_done, timeout=2.0)
+        except TimeoutError:
+            pytest.fail(f"Test 1 timed out. Values: {sensor_values['filter_min']}")
+
+        expected = [1.0, 12.0, -2.0]
+        assert sensor_values["filter_min"] == pytest.approx(expected), (
+            f"Test 1 failed: expected {expected}, got {sensor_values['filter_min']}"
+        )
+
+        # Test 2: Max
+        sensor_values["filter_max"].clear()
+        client.button_command(buttons["filter_max"])
+        try:
+            await asyncio.wait_for(filter_max_done, timeout=2.0)
+        except TimeoutError:
+            pytest.fail(f"Test 2 timed out. Values: {sensor_values['filter_max']}")
+
+        expected = [1.0, 5.0, 10.0]
+        assert sensor_values["filter_max"] == pytest.approx(expected), (
+            f"Test 2 failed: expected {expected}, got {sensor_values['filter_max']}"
+        )
+
+        # Test 3: Baseline Max
+        sensor_values["filter_baseline_max"].clear()
+        client.button_command(buttons["filter_baseline_max"])
+        try:
+            await asyncio.wait_for(filter_baseline_max_done, timeout=2.0)
+        except TimeoutError:
+            pytest.fail(
+                f"Test 3 timed out. Values: {sensor_values['filter_baseline_max']}"
+            )
+
+        expected = [1.0, 2.0, 3.0, 20.0]
+        assert sensor_values["filter_baseline_max"] == pytest.approx(expected), (
+            f"Test 3 failed: expected {expected}, got {sensor_values['filter_baseline_max']}"
+        )
+
+        # Test 4: Zero Delta
+        sensor_values["filter_zero_delta"].clear()
+        client.button_command(buttons["filter_zero_delta"])
+        try:
+            await asyncio.wait_for(filter_zero_delta_done, timeout=2.0)
+        except TimeoutError:
+            pytest.fail(
+                f"Test 4 timed out. Values: {sensor_values['filter_zero_delta']}"
+            )
+
+        expected = [1.0, 2.0]
+        assert sensor_values["filter_zero_delta"] == pytest.approx(expected), (
+            f"Test 4 failed: expected {expected}, got {sensor_values['filter_zero_delta']}"
+        )
diff --git a/tests/integration/test_udp.py b/tests/integration/test_udp.py
new file mode 100644
index 0000000000..74c7ef60e3
--- /dev/null
+++ b/tests/integration/test_udp.py
@@ -0,0 +1,171 @@
+"""Integration test for UDP component."""
+
+from __future__ import annotations
+
+import asyncio
+from collections.abc import AsyncGenerator
+import contextlib
+from contextlib import asynccontextmanager
+from dataclasses import dataclass, field
+import socket
+
+import pytest
+
+from .types import APIClientConnectedFactory, RunCompiledFunction
+
+
+@dataclass
+class UDPReceiver:
+    """Collects UDP messages received."""
+
+    messages: list[bytes] = field(default_factory=list)
+    message_received: asyncio.Event = field(default_factory=asyncio.Event)
+
+    def on_message(self, data: bytes) -> None:
+        """Called when a message is received."""
+        self.messages.append(data)
+        self.message_received.set()
+
+    async def wait_for_message(self, timeout: float = 5.0) -> bytes:
+        """Wait for a message to be received."""
+        await asyncio.wait_for(self.message_received.wait(), timeout=timeout)
+        return self.messages[-1]
+
+    async def wait_for_content(self, content: bytes, timeout: float = 5.0) -> bytes:
+        """Wait for a specific message content."""
+        deadline = asyncio.get_event_loop().time() + timeout
+        while True:
+            for msg in self.messages:
+                if content in msg:
+                    return msg
+            remaining = deadline - asyncio.get_event_loop().time()
+            if remaining <= 0:
+                raise TimeoutError(
+                    f"Content {content!r} not found in messages: {self.messages}"
+                )
+            try:
+                await asyncio.wait_for(self.message_received.wait(), timeout=remaining)
+                self.message_received.clear()
+            except TimeoutError:
+                raise TimeoutError(
+                    f"Content {content!r} not found in messages: {self.messages}"
+                ) from None
+
+
+@asynccontextmanager
+async def udp_listener(port: int = 0) -> AsyncGenerator[tuple[int, UDPReceiver]]:
+    """Async context manager that listens for UDP messages.
+
+    Args:
+        port: Port to listen on. 0 for auto-assign.
+
+    Yields:
+        Tuple of (port, UDPReceiver) where port is the UDP port being listened on.
+    """
+    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    sock.bind(("127.0.0.1", port))
+    sock.setblocking(False)
+    actual_port = sock.getsockname()[1]
+
+    receiver = UDPReceiver()
+
+    async def receive_messages() -> None:
+        """Background task to receive UDP messages."""
+        loop = asyncio.get_running_loop()
+        while True:
+            try:
+                data = await loop.sock_recv(sock, 4096)
+                if data:
+                    receiver.on_message(data)
+            except BlockingIOError:
+                await asyncio.sleep(0.01)
+            except Exception:
+                break
+
+    task = asyncio.create_task(receive_messages())
+    try:
+        yield actual_port, receiver
+    finally:
+        task.cancel()
+        with contextlib.suppress(asyncio.CancelledError):
+            await task
+        sock.close()
+
+
+@pytest.mark.asyncio
+async def test_udp_send_receive(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    """Test UDP component can send messages with multiple addresses configured."""
+    # Track log lines to verify dump_config output
+    log_lines: list[str] = []
+
+    def on_log_line(line: str) -> None:
+        log_lines.append(line)
+
+    async with udp_listener() as (udp_port, receiver):
+        # Replace placeholders in the config
+        config = yaml_config.replace("UDP_LISTEN_PORT_PLACEHOLDER", str(udp_port + 1))
+        config = config.replace("UDP_BROADCAST_PORT_PLACEHOLDER", str(udp_port))
+
+        async with (
+            run_compiled(config, line_callback=on_log_line),
+            api_client_connected() as client,
+        ):
+            # Verify device is running
+            device_info = await client.device_info()
+            assert device_info is not None
+            assert device_info.name == "udp-test"
+
+            # Get services
+            _, services = await client.list_entities_services()
+
+            # Test sending string message
+            send_message_service = next(
+                (s for s in services if s.name == "send_udp_message"), None
+            )
+            assert send_message_service is not None, (
+                "send_udp_message service not found"
+            )
+
+            await client.execute_service(send_message_service, {})
+
+            try:
+                msg = await receiver.wait_for_content(b"HELLO_UDP_TEST", timeout=5.0)
+                assert b"HELLO_UDP_TEST" in msg
+            except TimeoutError:
+                pytest.fail(
+                    f"UDP string message not received. Got: {receiver.messages}"
+                )
+
+            # Test sending bytes
+            send_bytes_service = next(
+                (s for s in services if s.name == "send_udp_bytes"), None
+            )
+            assert send_bytes_service is not None, "send_udp_bytes service not found"
+
+            await client.execute_service(send_bytes_service, {})
+
+            try:
+                msg = await receiver.wait_for_content(b"UDP_BYTES", timeout=5.0)
+                assert b"UDP_BYTES" in msg
+            except TimeoutError:
+                pytest.fail(f"UDP bytes message not received. Got: {receiver.messages}")
+
+            # Verify we received at least 2 messages (string + bytes)
+            assert len(receiver.messages) >= 2, (
+                f"Expected at least 2 messages, got {len(receiver.messages)}"
+            )
+
+            # Verify dump_config logged all configured addresses
+            # This tests that FixedVector<const char*> stores addresses correctly
+            log_text = "\n".join(log_lines)
+            assert "Address: 127.0.0.1" in log_text, (
+                f"Address 127.0.0.1 not found in dump_config. Log: {log_text[-2000:]}"
+            )
+            assert "Address: 127.0.0.2" in log_text, (
+                f"Address 127.0.0.2 not found in dump_config. Log: {log_text[-2000:]}"
+            )
diff --git a/tests/unit_tests/test_main.py b/tests/unit_tests/test_main.py
index fd8f04ded5..3268f7ee87 100644
--- a/tests/unit_tests/test_main.py
+++ b/tests/unit_tests/test_main.py
@@ -34,6 +34,7 @@ from esphome.__main__ import (
     has_non_ip_address,
     has_resolvable_address,
     mqtt_get_ip,
+    run_esphome,
     run_miniterm,
     show_logs,
     upload_program,
@@ -1988,7 +1989,7 @@ esp32:
     clean_output = strip_ansi_codes(captured.out)
 
     assert "test-device_123.yaml" in clean_output
-    assert "Updating" in clean_output
+    assert "Processing" in clean_output
     assert "SUCCESS" in clean_output
     assert "SUMMARY" in clean_output
 
@@ -3172,3 +3173,66 @@ def test_run_miniterm_buffer_limit_prevents_unbounded_growth() -> None:
     x_count = printed_line.count("X")
     assert x_count < 150, f"Expected truncation but got {x_count} X's"
     assert x_count == 95, f"Expected 95 X's after truncation but got {x_count}"
+
+
+def test_run_esphome_multiple_configs_with_secrets(
+    tmp_path: Path,
+    mock_run_external_process: Mock,
+    capfd: CaptureFixture[str],
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Test run_esphome with multiple configs and secrets file.
+
+    Verifies:
+    - Multiple configs use subprocess isolation
+    - Secrets files are skipped with warning
+    - Secrets files don't appear in summary
+    """
+    # Create two config files and a secrets file
+    yaml_file1 = tmp_path / "device1.yaml"
+    yaml_file1.write_text("""
+esphome:
+  name: device1
+
+esp32:
+  board: nodemcu-32s
+""")
+    yaml_file2 = tmp_path / "device2.yaml"
+    yaml_file2.write_text("""
+esphome:
+  name: device2
+
+esp32:
+  board: nodemcu-32s
+""")
+    secrets_file = tmp_path / "secrets.yaml"
+    secrets_file.write_text("wifi_password: secret123\n")
+
+    setup_core(tmp_path=tmp_path)
+    mock_run_external_process.return_value = 0
+
+    # run_esphome expects argv[0] to be the program name (gets sliced off by parse_args)
+    with caplog.at_level(logging.WARNING):
+        result = run_esphome(
+            ["esphome", "compile", str(yaml_file1), str(secrets_file), str(yaml_file2)]
+        )
+
+    assert result == 0
+
+    # Check secrets file was skipped with warning
+    assert "Skipping secrets file" in caplog.text
+    assert "secrets.yaml" in caplog.text
+
+    captured = capfd.readouterr()
+    clean_output = strip_ansi_codes(captured.out)
+
+    # Both config files should be processed
+    assert "device1.yaml" in clean_output
+    assert "device2.yaml" in clean_output
+    assert "SUMMARY" in clean_output
+
+    # Secrets should not appear in summary
+    summary_section = (
+        clean_output.split("SUMMARY")[1] if "SUMMARY" in clean_output else ""
+    )
+    assert "secrets.yaml" not in summary_section