The previous Task 4 handler installed onended on the *published* mic track,
but that track is a clone of AudioManager's MediaStreamAudioDestinationNode
output — destination-node tracks never end on upstream loss, they just go
silent. The handler also called setInputDevice for silent-recovery and assumed
syncMic would re-publish, but syncMic's dep array does not depend on
streamGeneration, so the recovery never republished.
This commit moves loss detection into AudioManager (where the upstream
getUserMedia track lives) via a new onInputTrackEnded subscription, extracts
republishMicrophone from syncMic into a module-level helper that both the
normal device-change path and the recovery path call directly, and removes
the published-track Microphone branch from RoomEvent.LocalTrackPublished.
The plan and Task 9 spec text are updated to match.
Jannis Braun
63bf9e684c