Lock the four-channel PCM-to-Bluetooth transport contract

[LordVicky]

Parent

#32

What to build

Add behavior-focused automated coverage for the complete in-process transport from interleaved four-channel USB PCM through speaker and actuator extraction to the native Bluetooth audio report. Correct only mismatches demonstrated by the new tests.

Acceptance criteria

• Verify speaker-left, speaker-right, actuator-left, and actuator-right mapping independently.
• Verify signed little-endian decoding, silence, positive and negative extrema, and mixed speaker/actuator input.
• Verify partial samples, partial frames, transfer tails, and chunk boundaries across multiple pushes.
• Verify simultaneous speaker payload and actuator payload in Bluetooth report 0x36.
• Verify report identity, payload placement, flags, sequence progression, and checksum validity through existing module interfaces.
• Prove that native audio does not automatically produce conventional rumble.
• Run the focused tests and the existing vDS protocol test suite with zero failures.
• Document any implementation correction with the failing contract evidence that justified it.

Blocked by

• Revalidate the current native-haptics hardware contract #33