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/heatfamily_reslice.cpp

@@ -337,16 +337,14 @@ void
 {
 	HeatableSubsystem *watched = (HeatableSubsystem *)watchedLink.Resolve();	// FUN_00417ab4(this+0x114)
 
-	// BRING-UP GUARD (marked deviation): in the shipped game watchedLink ALWAYS
-	// resolves -- the HeatWatcher resource's "WatchedSubsystem" name binds to a
-	// roster segment at load -- so the binary (FUN_004aeac4) derefs `watched`
-	// unconditionally.  Our port does not yet resolve the watch link, so Resolve()
-	// returns null; the deref AVs the moment a HeatWatcher-derived subsystem's
-	// Performance actually runs (exposed by the WAVE 4 un-stub: AmmoBinSimulation
-	// calls this directly; PowerWatcher::Simulation for Searchlight/ThermalSight).
-	// With no resolved source, hold the heat alarm at Normal (same established
-	// pattern as Emitter::TrackSeekVoltage's null-source guard).  FAITHFUL
-	// FOLLOW-UP = resolve watchedLink so the alarm tracks the real temperature.
+	// The watch link is now BOUND by the authentic factory connect pass (task
+	// #57: the mech factory's post-roster loop calls the binary's vtable slot
+	// +0x38 -- FUN_004aee2c / FUN_004b1a40 -> BTWatcherBindTarget below), so
+	// Resolve() succeeds on every master-node watcher whose resource named a
+	// WatchedSubsystem.  The binary derefs `watched` unconditionally; the null
+	// guard stays for replicant nodes (the binary never binds there either --
+	// the +0x38 body is master-gated -- and their watcher Performances don't
+	// run) and for bring-up safety.
 	if (watched == 0)
 	{
 		heatAlarm.SetLevel(0);						// NormalHeat (no watched source yet)
@@ -369,6 +367,51 @@ void
 	}
 }
 
+//
+// @004aee2c (HeatWatcher vtable slot 14, offset +0x38; the PowerWatcher/Torso
+// override @004b1a40 is byte-identical) -- the factory post-roster CONNECT
+// pass, disassembled from the raw binary (Ghidra missed both function starts):
+//
+//     owner = this->owner (+0xD0)
+//     if ((owner->simulationFlags & 0xC) == 0 && (owner->simulationFlags & 0x100))
+//         watchedLink(+0x114).Add( owner->roster(+0x128)[ watchedSubsystem(+0x128) ] )
+//
+// The mech factory loop tests IsDerivedFrom(HeatWatcher @0x50e604) then calls
+// the slot.  Split across the TU boundary the same way as the other
+// cross-family helpers: the OWNER-side master gate + roster lookup live in the
+// mech family (complete Mech type); these two bridges are the family-side
+// derivation test and the link Add.  [T1: bytes @004aee2c/@004b1a40]
+//
+int
+	BTWatcherWatchedIndex(Subsystem *sub)		// -1 = not a HeatWatcher
+{
+	if (sub == 0 || !sub->IsDerivedFrom(*HeatWatcher::GetClassDerivations()))
+	{
+		return -1;
+	}
+	return ((HeatWatcher *)sub)->watchedSubsystem;		// @0x128 (resource +0xE4, name index +2)
+}
+
+void
+	BTWatcherBindTarget(Subsystem *sub, Subsystem *target)
+{
+	((HeatWatcher *)sub)->watchedLink.Add(target);		// (**(link+4))(link, target) = FUN_00417a80
+}
+
+//
+// Cross-family derivation probe: 0x50e604 is the HEATWATCHER derivation tag
+// (TestInstance @4aec38 checks its own class against it) -- NOT HeatSink, as
+// an old btl4gaug label claimed (HeatSink : HeatableSubsystem would make an
+// OR-test after HeatableSubsystem redundant; the binary's alternate branch is
+// the disjoint watcher family).  Bridged so gauge TUs can test without
+// including this family's headers.
+//
+int
+	BTIsHeatWatcher(Subsystem *sub)
+{
+	return sub != 0 && sub->IsDerivedFrom(*HeatWatcher::GetClassDerivations());
+}
+
 //
 // @4aec54 (468 bytes) -- parse the HeatWatcher resource.  Stamps classID 0x0BBF
 // / size 0xF0; defaults the watched index to -1; requires DegradationTemperature,