Audio realism: spatial audio capture to simulated microphone inputs

[Kinin-Code-Offical]

Goal: Unity scene audio (spatialized/surround) can be captured and fed into simulated microphone devices used by firmware/ROS nodes.

Scope:

• Define mic devices + sample format/rate.
• Capture Unity mix/per-source mix and publish frames to simulation bus.
• Deterministic option for tests.

Acceptance:

• Mic samples available to RPi guest path and/or MCU ADC-style inputs.