Replace the single-owner PCM queues with one shared LGMP SPMC stream.
Give each admitted client reliable state and an independent playback
cursor, while clients without clock authority resample locally.
Extend the audio protocol with per-client epochs and barriers.
Keep capture exclusive and bound authority backpressure so slow
secondary readers cannot affect the disciplined low-latency path.
Add LGProtocol as a pinned submodule and consume its KVMFR protocol
definitions throughout the client, host, IDD, OBS, and profiler.
Keep Looking Glass framebuffer helpers local while removing duplicated
protocol headers and migrating users to KVMFR-scoped types.