Today's authentic trn dispatcher folded the master-perf turn-STOP exit into leg/body
case 4. But the master perf (FUN_004a9b5c) runs on MasterInstance mechs, NOT
replicants -- and a replicant derives turnDemand from the noisy REPLICATED yaw rate
(mech4.cpp:1968), which dips into the +-0.05 deadband between dead-reckon updates. So
the exit kicked the peer out of trn every few frames -> the peer 'rotated as a statue'
+ jerky (user-reported regression from yesterday). Gate both turn-stop exits to
GetInstance() != ReplicantInstance; the replicant advances the trn clip from its
replicated turn signal exactly as before the exit was added. Also BT_REPL_TRN probe
(mech4.cpp) logs the replicant yawRate/turnDemand/legState.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
