Replace the temporary std::vector copy with in-place compaction using a
read/write pointer pattern. This avoids a heap allocation+deallocation
cycle during scheduler cleanup, reducing heap fragmentation on
long-running ESP devices.
The new approach compacts valid items forward in the existing vector,
recycles removed items as they are encountered, then resizes the vector
(no reallocation since size only shrinks). Same O(n) complexity, same
behavior, zero allocations.
fa1554cac0