KB housekeeping sweep: end-of-arc staleness purge (2026-08-06)

Corrections (wrong claims fixed + swept):
- open-questions: the DuckState 'no CODE consumer, authentic [T1]' verdict
  RETRACTED (consumer = the unexported posture block; squat clips shipped in
  BTL4.RES all along); the searchlight fog swap re-marked DONE (was 'STILL
  DEFERRED'); crouch index pointer updated.
- combat-damage: old task-#60 kill-score section marked SUPERSEDED by the
  report tail (BTPostKillScore retired).
- pod-hardware: crouch census rows -> COMPLETE; gauges-hud: 07-20 note
  (generators 'unreconstructed') re-swept.

New knowledge:
- reconstruction-gotchas #20: EXPORT-GAP BLINDNESS (4 incidents, 2 falsely
  T1; the byte-scan/named-member/RES-TOC/manifest checklist) + the
  verification-viewpoint bullet in #13 (the crouch capture errors).
- decomp-reference: master posture/crouch block offsets (+0x3f8/+0x79c, the
  myomers cluster) + 8 new bench env gates.
- rendering: beam-material decode (btfx brighten) + look-pass acceptance.
- experience-levels: crouch novice lockout in the +0x25c consumer list.
- build-and-run: the stale-link build ritual; test-harness: bench-script
  gotchas (both previously oral tradition).
- glossary: export-gap-blindness; multiplayer: crouch/searchlight ride
  existing records; subsystems: searchlight visuals pointer.

Status refresh: CLAUDE.md front + project-overview current-state -> core
gameplay reconstruction COMPLETE (774->801), polish phase, #60 census next.
Ledger addenda: INPUT_PATH row 6 complete; RESPAWN_REARM VehicleDead-sender
note. .gitignore: content/ bench artifacts (pngs/logs/eggs/exe) out of
status. checkctx CLEAN.

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

context/decomp-reference.md

@@ -176,6 +176,22 @@ rows until sanity fails (`python + struct`, see the session commits `cc2b109`/`2
 
 ---
 
+### Master posture / crouch block (FUN_004a9b5c region, raw disasm 2026-08-05/06) [T1]
+- mech+0x3f8 `mapPosture` (0 none / 1 may-duck / 2 holding-squat) — selector @0x4a9f61-0x4aa007:
+  gates = movementMode normal, simLive (player+0x25c, NOVICE lockout), leg alarm 0/4 → 1, leg
+  alarm 1 → 2, myomer factor |x|>1e-4 (const @0x4ab16c).
+- mech+0x79c `myomerEffectiveness` — MAX over the myomer chain's speedEffect@0x31C, published by
+  the mapper drive-scale block (mechmppr.cpp:990 == @0x4a9cf2-0x4a9da4); scales speedDemand,
+  zeroes turnDemand at ~0 (the seek-4 freeze), and gates the crouch.
+- DuckRequest consumer @0x4aa011-0x4aa0af: duckState && squatCapable → SetLegAnimation(2 'sqd')
+  / (3 'squ'), ForceUpdate(8)+(1) (type-3 record ships legState → peers pose it), stability
+  alarm 0/1, request consumed.  Clips: animationClips[2]=sqd(i), [3]=squ(i) (BTL4.RES, all 8
+  chassis; loader slots byte-verified vs @0x50d9c8 suffix pool).
+- Myomers cluster: Performance wrapper @004b8b9c → drive-heat integrator @004b8be3;
+  AvailableOutput @004b8ac0 = gear clamp × QUADRATIC heat degrade (+0x114 vs +0x118/+0x11c band)
+  × (1 − legZoneDamage); speedEffect = output / ownerBaseSpeed(+0x34C) — unclamped (gear-4
+  supercharge ≈1.43).
+
 ## 4. Damage delivery
 
 - `Entity::TakeDamageMessage(id, size, inflictingEntityID, zone, Damage&)` → `target->Dispatch(&msg)`.
@@ -531,6 +547,13 @@ default-ON (`'0'` disables).
 | Var | Effect |
 |---|---|
 | `BT_FORCE_THROTTLE` | auto-walk forward (no key) |
+| `BT_BTNTEST=addr,on,off` / `BT_BTNTEST2=...` | scripted screen-button press/release cycles at poll counts (the REAL RIO seam; 2nd cycle for e.g. squat→rise) |
+| `BT_DUCK_LOG` | crouch diagnostics: RIO press mode-mask, SetLegAnimation re-arm tracer (+ra), 1 Hz joint probe, posture/squat events |
+| `BT_TREE_LOG` | dump the built render-tree topology (segment/joint/parent, SITE rows) at mech build |
+| `BT_SPOT_SELF` | bench-only: build the searchlight cone on the OWN-cockpit tree so `BT_CAM=face` can eyeball it solo |
+| `BT_CAM=face` | chase camera in FRONT looking back (the old animation view); `BT_CAM_Y/Z` offsets |
+| `BT_FOG_LOG` | log SetFogStyle transitions + fog page resolution (searchlight swap forensics) |
+| `BT_GIMP_SPEED` | override the gimp-gait demand scale (1.0 = authentic) |
 | `BT_SPAWN_ENEMY` | spawn a target mech 120u ahead along the spawn facing |
 | `BT_AUTOFIRE=1` | hold the trigger (headless walk→fire→death harness; supersedes the dead `BT_FORCE_FIRE` — btl4main.cpp:310 set `fireForced` once at startup, but mech4.cpp:1567 unconditionally overwrites it every frame) |
 | `BT_ASSERT_TO_DEBUGGER` | route CRT asserts to the debugger, not a modal box |