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.
Make CSRWLock own the native lock and provide scoped guards for shared,
exclusive, early-unlock, and non-blocking use.
Replace direct SRW lock management throughout the IDD, input driver,
and helper while preserving the existing lock scopes.
Introduce transport, frame, and control interfaces with an LGMP factory
backend.
Move LGMP and IVSHMEM implementation details under transport/lgmp and
expose direct frame-buffer memory through a neutral capability.
