Integrate bounded armed OBS audio capture and transport

[RioPlay]

The armed OBS session previously stopped after consent and lifecycle gating; it did not deliver stream audio to the desktop. This change connects the selected OBS streaming mixes to bounded callback queues, performs worker-side stereo conversion, sends ordered Start/Audio/Gap/End packets, and requires a session-bound End acknowledgement before normal disconnect.

This is stacked on #37. It adds the pinned public audio API inputs, native protocol/queue/conversion/capture/transport components, generation-checked message-only frontend dispatch, runtime lifecycle integration, and desktop terminal-receipt handling. Callback work remains bounded and contains no allocation, conversion, I/O, or OBS control calls.

Validation:

• 24 build commands and 51 native verification commands passed.
• The native driver included 84 focused Windows pipe, Arm, and terminal-receipt Python tests.
• Receipts bind 67 native sources, 14 desktop inputs, 23 artifacts, and 51 logs; 331 hashes were compared.
• Build receipt: 4b2b262a1cf66e15df26a3fc2623b263a7e791cb8fbd2b34a05f77cf2534a3fa.
• Test receipt: eee66813c7ae6051a4db5817839dbab25c2543c043cfe2f43e2a51f3f770fe69.
• Headless smoke receipt: 7b3501c377df8130b10fe470b18a9ffdd98aae673f438b09187ee2578cef1fc5.

The evidence covers synthetic/native components, the linked development DLL, bounded teardown, stale frontend work, and headless refusal. It does not establish live OBS frontend/audio compatibility, device behavior, controller or recognition behavior, installation, publication, or redistribution readiness. No OBS application, audio device, consumer pairing/configuration, desktop release, or Android release was changed.