KB: crit-propagation landing recorded (task #2)

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

context/combat-damage.md

@@ -291,6 +291,15 @@ Full decomp map of the death path. Two tiers:
   accessors ride the engine StateIndicator, which is why the death state (9) now REPLICATES --
   it travels in every update record's header (+0xC) and the observer's replicant runs its own
   wreck sink off it (see [[multiplayer]] "Mech-level update records"). [T1]
+- **✅ Critical-subsystem propagation LIVE (task #2, 2026-07-11) [T2]:** a zone driven to 1.0
+  cascades its streamed crit allotments into the carried subsystems' OWN private DamageZones
+  (SendSubsystemDamage @0049c9a8, rewritten to the recovered body); a subsystem at 1.0 fails
+  (statusAlarm Destroyed + zone valve), a VITAL one (`vitalSubsystem@0xE4`, ex "videoObjectFlag")
+  kills the mech via graphicAlarm 9.  The plugs bind in the zone ctor
+  (`SlotOf<Subsystem*>.Add(subsystemArray[streamedIndex])` @0049d0e1 — Ghidra had dropped the
+  call's arguments, hiding the binding for the whole effort); `CriticalHit` uses the real
+  `ApplyDamageAndMeasure` @4ac07c.  Diag: `BT_CRIT_PROBE=<zone>`.  Detail: [[open-questions]]
+  (the resolved entry) + mechdmg.cpp/mechsub.cpp.
 - **`MechDeathHandler`** (ctor `FUN_0042a984` + Performance `FUN_0042aa2c`, cached mech+0x850 / `mech[0x214]`) —
   the **per-subsystem destroyed-skin + explosion engine**. Each tick walks the damage subsystems
   (mech+0x120[mech+0x11c]); as a subsystem's damage crosses a descriptor-table threshold (`FUN_0042a5f4`

context/decomp-reference.md

@@ -175,6 +175,7 @@ default-ON (`'0'` disables).
 | `BT_WARP_SELFTEST` / `BT_WARP_SELFSHOT=<prefix>` | DIAG (off by default): force a held warp in a solo game / dump backbuffer frames to disk (visual-verification harness) |
 | `BT_GYRO_LOG` | gyro bring-up log (gyro.cpp) |
 | `BT_GYRO_TRACE` | per-frame hit-bounce integrator trace |
+| `BT_CRIT_PROBE=<zone>` | hammer one own-mech zone every 4s (crit-propagation diag, task #2; mech4.cpp) |
 | `BT_REPL_LOG` | replicant/MP replication log (mech4.cpp) |
 | `BT_GOTO="enemy"\|"x z"` / `BT_GOTO_LOG` | self-driving beeline (to the enemy or a map coordinate) + its log |
 | `BT_MP_LOG` / `BT_MP_NET` / `BT_MP_FORCE_DMG` | MP diagnostics / forced cross-pod damage |