User confirms 'way better'; single-player un-regressed (master walks correctly,
the bodyTargetSpeed change only affects the invisible mj=0 body channel).
Flip the authentic-coupled path ON by default:
- peer position: gait-coupled linear (was velocity dead-reckon); BT_DR_POS=1 reverts
- master send-mirror: gait projection of projectedOrigin; BT_NO_MASTER_GAITMIRROR reverts
The two-source split (position from velocity + animation from commanded speed)
that mismatched during speed changes is retired. Residual: occasional ~2.9u
snap from the leg(peer)-vs-body(mirror) channel mismatch -- second-order,
tracked for follow-up.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>