#82 FINAL LAYER: the peer body-channel trn-lock -- a circling limper skated because the peer's turn-arm had no walk-demand yield and the trn speed exit read a dead replicant mapper cell

The master limped clean (218x gimp-cycle records, zero trn) -- a _ReturnAddress
trap on SetAnimationState(4) proved ALL peer trn arming came from the port's own
mech4 turn-step block, not the type-3 reader.  Two dead ends, one root:
- mech4 peer arm: gated on !wantsWalk (standSpeed < bodyTargetSpeed), exits trn
  when walking demand appears -- the leg twin's authentic precedence
  (part_012.c:12013, the Standing speed test outranks the turn test).
- mech2 body case 4: bspd reads bodyTargetSpeed on ReplicantInstance; the local
  mapper's speedDemand is a dead cell on a peer (reads 0 forever -> no exit).
Verified 2-node timeline: arena circle replicant 218x state-24 / 0x state-4
(was 116x trn churn), grass circle 235-clean, knockdowns bounded, 0 deaths.
Diagnostics kept: BT_TRNTRAP ra-trap, BT_ANIMIND_CAP, [gimpfeed], [replgimp]
extension.  KB: locomotion.md trn-lock entry + the dead-mapper-cell lesson.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QRjrTQpJd6u9XyfnUbTB3v

game/reconstructed/mech4.cpp

@@ -2436,10 +2436,19 @@ void
 					const int  bs = (int)bodyStateAlarm.GetLevel();
 					const bool turning = (replMppr->turnDemand > 0.05f
 									   || replMppr->turnDemand < -0.05f);
-					if (turning && bs == 0)			// standing + turning -> enter turn
+					// YIELD TO WALK DEMAND (#82 trn-lock): the master only sits in
+					// trn when its commanded speed is at stand (the leg Standing
+					// case's speed test wins first, part_012.c:12013).  A circling
+					// LIMPER keeps full demand (bts~24) while its yaw rate reads as
+					// turning here -- ungated, this block pinned the peer in body
+					// case 4 (advance-only, no exit) forever = the skating.  Mirror
+					// the leg twin's precedence: walking demand outranks the pivot.
+					const bool wantsWalk = (standSpeed < bodyTargetSpeed
+										 || bodyTargetSpeed < 0.0f /*reverse*/);
+					if (turning && bs == 0 && !wantsWalk)	// standing pivot only
 						SetBodyAnimation(4);
-					else if (!turning && bs == 4)	// turn stopped -> back to stand
-						SetBodyAnimation(0);
+					else if (bs == 4 && (!turning || wantsWalk))
+						SetBodyAnimation(0);	// stand; case 0 walk-begins next tick
 				}
 				// GIMP routing (#78): a limping PEER runs the gimp machines too
 				// (the graphicAlarm level replicates with the damage state).
@@ -2456,6 +2465,9 @@ void
 						s_ga = 0.0f;
 						DEBUG_STREAM << "[replgimp] ent=" << (int)GetEntityID()
 							<< " gl=" << replGl
+							<< " bts=" << bodyTargetSpeed
+							<< " standSpeed=" << standSpeed
+							<< " bodyState=" << (int)bodyStateAlarm.GetLevel()
 							<< " sim=" << (int)GetSimulationState()
 							<< " hasClips=" << hasGimpClips << " zones:";
 						for (int zi = 0; zi < damageZoneCount; ++zi)