the rest of the Myomers wrapper: two live outputs recovered, and one branch that never fires

Follow-on to b70654d, which chained the base sim and stopped there. Decoding
the remaining 0x17c bytes of @004b8b9c turned up four more blocks the port had
dropped along with it. In binary order the registered Performance is:

  @004b8bab  chain PoweredSubsystemSimulation                  (fixed in b70654d)
  @004b8bb9  un-powered self-repair of this myomer's own zone   (dead -- see below)
  @004b8c1e  republish outputVoltage@0x344 from the source
  @004b8c5a  republish speedEffect@0x31C, the drive fed to the mover
  @004b8ceb  run the inner integrator, ONLY when outputVoltage > 0

speedEffect is the interesting one. AvailableOutput scales by the Mech base
speed and the wrapper divides by it again, so the two cancel and what lands in
+0x31C is a 0..1 FRACTION of full drive carrying the gear ratio, the thermal
degradation curve and the accumulated zone damage. Neither it nor outputVoltage
was ever written before: outputVoltage sat wherever the ctor left it and
speedEffect stayed pinned at its ctor 1.0f.

Un-stubbed DamageStructureLevel() while in here. It was `return 0.0f`, which
held AvailableOutput's (1 - damage) factor at 1, so a shot-up myomer drove
exactly as well as a fresh one. Routed to the base's GetSubsystemDamageLevel()
bridge, the same cell sensor.cpp:312 already reads. Measured dmg=0.6 -> speed=0.4.

@004b8bb9 does not work, and did not work in 1995 either. It builds a Damage
(Explosive, amount 0xbc343958 ~= -0.011f, impactPoint from owner+0x100, burst 1)
and calls the ZONE's TakeDamage -- vtable +0x18, not the subsystem's +0x24 -- so
the plain `damageLevel += amount * damageScale[type]`. Read on its own that is
"a myomer you power down slowly heals". But a subsystem's private zone is built
by the 2-arg `new DamageZone(this, 0)`, and DAMAGE.cpp:187-190 zeroes all five
damageScale entries; Reset never touches them and the only other writer is
Mech__DamageZone, the mech's streamed zones. The sum is always `+= amount * 0`.
Seeded a zone to 0.6, held it at NoVoltage for ~1500 ticks: damageLevel never
moved. Reconstructed and deliberately not "fixed" -- a working repair here would
be behavior we invented. The crit path reaches subsystem damage by writing
damageLevel directly, which is why subsystems still die.

That generalises, so it is written up in context/combat-damage.md on its own:
you cannot damage a subsystem's own zone through DamageZone::TakeDamage at all.
Anything reconstructed later that means to hurt a subsystem has to go the way
the crit path goes, or it will silently do nothing.

Verified, self-damage runs across two death/respawn cycles:
  torso    96/96 samples elec=4, zero dips
  myomers  96/97 elec=4 (the odd one is the first tick, before the machine runs)
  healthy  outV=10000 speed=1     un-powered  outV=0 speed=0

BT_MYOMERS_LOG probes the four outputs; BT_MYOMERS_REPAIR_TEST=<level> seeds the
zone and drops the subsystem into Manual so the repair branch can be watched
without the AutoConnect hunt restoring power a frame later.

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

game/reconstructed/mechsub.cpp

@@ -421,6 +421,22 @@ Scalar
 	return ((DamageZone *)damageZone)->damageLevel - before;
 }
 
+//
+// Straight to the zone's own virtual -- see the header note.  Myomers'
+// Performance (@004b8c0f-0x4b8c1b) does exactly:
+//     eax = this[0xE0];  (*(*eax + 0x18))(eax, &damage)
+// i.e. DamageZone::TakeDamage, whose T0 body (engine/MUNGA/DAMAGE.cpp:374) is
+//     damageLevel += damageAmount * damageScale[damageType];
+//     Clamp(damageLevel, 0.0f, 1.0f);  SetDamageLevelChangedFlag();
+// so a NEGATIVE damageAmount walks the zone back toward intact, and the clamp
+// is what stops it below 0.
+//
+void MechSubsystem::ApplyZoneDamage(Damage &damage)
+{
+	if (damageZone != 0)
+		((DamageZone *)damageZone)->TakeDamage(damage);	// zone vtable +0x18
+}
+
 //
 // @0x4ac274 -- the AMMO-EXPLOSION fan-out (Gitea #46, re-read from the raw
 // decomp).  The old reconstruction here was wrong in kind: it "re-applied the