Move audio ingress and playback-credit recovery off the display timer.
Poll through a dedicated MMCSS worker at sub-millisecond intervals.
Wake capture retries immediately and drain queued client records during
release so backpressure cannot stall recording or shutdown.
Add optional playback and capture streams to the LGMP transport.
Negotiate ownership over the existing control path and keep audio
availability isolated from display transport readiness.
Route broker packets through public LGMP stream APIs without changing
the LGMP queue table or shared-memory mapping.
Open the optional audio broker from a passive worker and move bounded
playback and capture packets through a transport-neutral audio hub.
Attach audio sources after transport initialization without making audio
driver availability part of display transport readiness.
