BT410 Phase 5.3.17: the destruction cascade -- zone deaths DESTROY things

Mech::DamageZone::TakeDamage is the full binary cascade (@0049c690): LOD
artifact router with same-attacker clustering (@0049c40c, hysteresis 0.33),
artifact parent level = mean of children, Energy-hit generator shorts
through the crit plug binding (novice-exempt), weighted CriticalHit
(@0049ccc4), zone-death allotment push (SendSubsystemDamage @0049c9a8) and
the segment-table destruction descent (RecurseSegmentTable @0049cad4 --
SIBS + DESCEND via the engine EntitySegment iterators).

Supporting bricks: Mech's OWN handler table with the TakeDamage override
(latches lastInflictingID @0x43c; gyro feed staged; cylinder table
deferred); friend class Mech__DamageZone (authentic); subsystem private
zones ARMED (structureReference + armorByFacing[5] normalized -- crits are
measurable); ApplyDamageAndMeasure; ForceCriticalFailure sets
DestroyedState so the weapon FSMs' GetSimulationState()==1 hard gate went
live; Generator::ForceShort + PoweredSubsystem::ForceShortRecovery.

Fight-verified (mutual BT_SPAWN_ENEMY + BT_FORCE_ZONE=8 concentrated fire):
arm zone to 1.0 -> sibling searchlight zone dies (Searchlight2/ThermalSight
crits destroyed, HUD degrading) -> DESCEND kills the gun zone -> PPC_2 +
ERMLaser_2 + Condenser6 DESTROYED and FALL SILENT (0 shots after death;
undamaged PPC_1 keeps firing); vital-zone hit = MECH KILL; PPC hit shorted
GeneratorD. This art has zero artifact zones (redirect=0 across all 20 --
router verified dormant-correct). Smoke + novice regressions clean.

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

restoration/source410/BT/MECH.CPP

@@ -64,10 +64,29 @@ Derivation
 		"Mech"
 	);
 
+//
+// The Mech's OWN handler table, chained to the JointedMover set.  The
+// TakeDamage entry OVERRIDES Entity's by message ID (Build overlays the
+// inherited slot -- no gap risk, the parent chain already registered the
+// ID); every other inherited message still routes to its base handler.
+//
+const Receiver::HandlerEntry
+	Mech::MessageHandlerEntries[] =
+{
+	MESSAGE_ENTRY(Mech, TakeDamage)
+};
+
+Mech::MessageHandlerSet
+	Mech::MessageHandlers(
+		ELEMENTS(Mech::MessageHandlerEntries),
+		Mech::MessageHandlerEntries,
+		JointedMover::MessageHandlers
+	);
+
 Mech::SharedData
 	Mech::DefaultData(
 		Mech::ClassDerivations,
-		JointedMover::MessageHandlers,
+		Mech::MessageHandlers,
 		JointedMover::AttributeIndex,
 		33,
 		(Entity::MakeHandler)Mech::Make
@@ -167,6 +186,7 @@ Mech::Mech(
 	lookPitch			= 0.0f;
 	lookYaw				= 0.0f;
 	targetEntity		= NULL;
+	lastInflictingID	= EntityID::Null;
 
 	//
 	// Look-view angles: defaults until the GameModel read below overrides them
@@ -551,6 +571,41 @@ Mech::~Mech()
 {
 }
 
+//
+//#############################################################################
+// TakeDamageMessageHandler -- the Mech override of the Entity damage entry
+// (binary hub @004a0230 via the handler glue @0049ed0c).
+//
+// Order in the binary: (1) feed the RAW Damage record to the gyro cockpit
+// bounce FIRST -- even an invalid-zone hit shakes the cockpit (STAGED: the
+// gyro bounce math is the gyro/feel wave; a gated log marks the feed site);
+// (2) latch the attacker (mech+0x43c -- the zone LOD router keys its
+// same-attacker redirect reuse off it); (3) resolve an unaimed hit's zone
+// (invalidDamageZone) from the cylinder hit-location table -- DEFERRED, the
+// type-0x1d table is not loaded yet, so unaimed hits fall through to the
+// base handler's zone==-1 drop (authentic base behavior); (4) chain to the
+// Entity handler which routes damageZones[zone]->TakeDamage.
+//#############################################################################
+//
+void
+	Mech::TakeDamageMessageHandler(TakeDamageMessage *message)
+{
+	Check(this);
+	Check(message);
+
+	if (gyroSubsystem != NULL && getenv("BT_MECH_LOG"))
+	{
+		DEBUG_STREAM << "[gyro] hit feed staged (type="
+			<< (int)message->damageData.damageType
+			<< " amt=" << message->damageData.damageAmount << ")"
+			<< endl << flush;
+	}
+
+	lastInflictingID = message->inflictingEntity;
+
+	Entity::TakeDamageMessageHandler(message);
+}
+
 void
 	Mech::SetMappingSubsystem(Subsystem *subsystem)
 {