Torso: the TWIST goes LIVE -- electrical watchdog chain, centered crosshair, coherent controls (task #57/#58)

The MadCat torso twists, the view turns with it, and targeting follows.
Three reconstruction fronts closed:

THE ELECTRICAL WATCHDOG CHAIN (why the torso never powered up):
- PowerWatcher::UpdateWatch reconstructed (@004b181c, the REAL registered
  Performance -- PTR @0050f5fc; Ghidra missed the fn start): the watchdog
  MIRRORS the watched subsystem's electrical level (+0x278), brownout
  downgrade when gen output <= minVoltage% x rated.  @004b1804 relabeled
  ResetToInitialState (slot 10) -- the old "Simulation" tag was wrong.
- The factory watcher-CONNECT pass reconstructed (vtable slot +0x38,
  @004aee2c/@004b1a40 byte-identical, recovered from raw exe bytes):
  watchedLink.Add(roster[watchedSubsystem]) on the master node.  Was the
  SubProxy::Start() no-op -- every watchdog sat at 0 forever.
- MinVoltageScale = 0.01 (a 10-byte x87 literal @0x4b1924; was 1.0f =
  permanent brownout) and PowerWatcher's Derivation chains its REAL base
  HeatWatcher (the HeatableSubsystem stand-in broke IsDerivedFrom for the
  whole Torso/Searchlight/ThermalSight family).
- KB correction swept: derivation tag 0x50e604 = HEATWATCHER (not
  "HeatSink"); the btl4gaug heat-widget gate now tests it via the
  BTIsHeatWatcher bridge.

THE CROSSHAIR (task #58 forensics, 6-agent workflow + live probes):
- The VIEW is TORSO-MOUNTED: jointtorso -> jointeye -> siteeyepoint in
  every twist-capable .SKL; the camera + canopy ride the same hinge
  subtree through HingeRenderable's live matrix-stack compose -- ALREADY
  WORKING in the port.  The crosshair stays screen-centered (center IS
  the boresight); the twist reads on the tape carets/compass/radar.
- The real bug was the port's gBTAimX = tan(twist) slew (the falsified
  "body-mounted view" model): the camera already carried the twist, so
  the crosshair counter-slid to hull-forward and the fire ray with it.
  Deleted; the pick ray inherits the twist from the yawing eye basis.
- Two instrumentation traps documented (chase-eye-as-default-camera,
  BT_FORCE_TORSO clobbering real joints -> the hook now only fills
  unresolved ones); an over-correcting explicit eye compose was added on
  those false readings and retired the same day.

CONTROLS + REPLICATION:
- Q/E spring-center on release (the axis is a twist-RATE demand; the old
  hold-deflection model drifted forever); X also zeroes the axis and
  pulses the authentic torso Recenter (@004b6918).  M cycles control
  mode via the real CycleControlMode body.
- Torso update-record DIRECTION fixed: engine truth is Write=serialize /
  Read=apply; @004b6a78 is the READ (was mislabeled Write) and the
  missing WRITE @004b6a1c recovered from raw disasm (recordLength 0x1C,
  twist/vel/rate at +0x10/14/18) -- kills the replicant's 0xCDCDCDCD
  -140-degree ghost twist.
- Marching-ghost desync: 4 Standing-case guards zero stale reverse
  cycleSpeed (negative cadence passed the <= ZeroSpeed stop gate).
- Kill credit rerouted to the OBSERVED killer (lastInflictingID ->
  killer's player link) -- kills count, target K/D populates.

KB: subsystems.md (watcher chain), multiplayer.md (record direction),
combat-damage.md + gauges-hud.md + cockpit-view.md (torso-mounted view
re-correction), decomp-reference.md (new addresses + tag fix),
open-questions.md (dead capability-roster loops 2-4, snapshot CD read).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

game/reconstructed/btl4gaug.cpp

@@ -52,7 +52,8 @@
 //      FUN_0044a5b4/5dc  GraphicsViewRecord ctor/dtor
 //      FUN_0044a650/630  GraphicsViewRecord Erase / Reset
 //      DAT_00524e20  DebugStream (warning channel)
-//      0x50e3ec / 0x50e604   heat-subsystem class-derivation tables
+//      0x50e3ec / 0x50e604   heat class-derivation tags (HeatableSubsystem /
+//                            HEATWATCHER -- task #57 relabel; was "HeatSink")
 //
 // GraphicsView vtable slots used below (this+0x48):
 //      +0x08 SetExtent  +0x10 SetOrigin  +0x18 SetColor  +0x24 MoveTo
@@ -363,9 +364,12 @@ void
 //
 // HeatConnection -- @004c3664 ctor / @004c3720 Transfer.
 //   ctor: source = the heat subsystem; flag@0x14 records whether it is the
-//   "primary" heat class (IsDerivedFrom 0x50e3ec) vs. the alternate (0x50e604);
-//   destination@0x18.  Transfer: no subsystem -> 100 ; subsystem operational
-//   (+0x40 == 1) -> 100 ; else Round( Resolve(subsys+0x114 currentTemperature) ).
+//   "primary" heat class (IsDerivedFrom 0x50e3ec HeatableSubsystem) vs. the
+//   alternate (0x50e604 = HEATWATCHER, task #57 relabel); destination@0x18.
+//   Transfer: no subsystem -> 100 ; subsystem operational (+0x40 == 1) -> 100 ;
+//   else Round( Resolve(subsys+0x114) ) -- NB for a Heatable that offset is
+//   currentTemperature, for a WATCHER it is watchedLink (the flag@0x14 likely
+//   picks the read; the watcher path is unverified [T4]).
 //   Used by ColorMapperHeat -- THIS is the heat gauge's data feed.
 //
 // All Transfer bodies are reproduced inside the owning gauge's notes; the
@@ -925,8 +929,13 @@ ColorMapperHeat::ColorMapperHeat(
 		// The subsystem MUST be heat-bearing (one of the two heat class
 		// derivation tables) or the data feed is meaningless.
 		//
+		extern int BTIsHeatWatcher(Subsystem *sub);	// heatfamily_reslice.cpp bridge
 		if (!subsystem->IsDerivedFrom(*HeatableSubsystem::GetClassDerivations()) &&	// FUN_0041a1a4 (0x50e3ec)
-			!subsystem->IsDerivedFrom(*HeatSink::GetClassDerivations()))			// (0x50e604)
+			!BTIsHeatWatcher(subsystem))			// (0x50e604 = HEATWATCHER -- task #57 relabel:
+													// the old "HeatSink" reading was redundant after
+													// the HeatableSubsystem test; the binary's
+													// alternate branch is the disjoint WATCHER family
+													// (ammo bins / torso carry a mirrored heatAlarm))
 		{
 			Verify(False);	// FUN_0040385c -- "Bad subsystem type" BTL4GAUG.CPP:0x68a
 		}