KB: reconcile the context system with the day's work

- decomp-reference.md: the binary ATTRIBUTE-TABLE section -- 16-byte
  {id,name,off+1,0} row format (alignment warning), the walker technique,
  and the three recovered tables (Mech ids 21-56 incl the corrected
  EyepointRotation@0x360 / RearFiring@0x410 / DistanceToMissile@0x400
  labels; HeatSink 3-12; Torso 3-15; the weapon RearFiring 'b' marker).
- combat-damage.md: the REAR-FIRE + look-view system (roster survey: the
  Blackhawk's ERMLaser_2/3 are the game's only rear weapons; every missile
  rack forward), the missile mount-frame launch truth, and the BANKED
  full Missile flight-model decode (three performances, proximity fuse).
- wintesla-port.md: post-Phase-4 closures (instability model live, F14
  static filter baked, the footstep warm-up bug + its trace-cap lesson);
  deferred list trimmed to F21/HRTF.
- AUDIO_FIDELITY.md: status block -- F14 FIXED, warm-up bug noted.
- open-questions.md: "which mechs used rear fire" answered from data;
  remaining look-view key bindings noted.
checkctx: CLEAN.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docs/AUDIO_FIDELITY.md

@@ -2,11 +2,13 @@
 
 > **STATUS (2026-07-16): Phases 1-4 SHIPPED** (commits fc7f311, 691e885, 0ca7d26,
 > cc2b109..0e2401f).  Fixed: F1-F5, F7, F9-F13, F15, F16, F18-F20, F23, KB items;
-> F6 fixed (ReportLeak -> coolantActive@0x138, binary table [T1]); F14 partial
-> (attenuation baked; static fc/Q deferred); F17 FIXED (CollisionSpeed +
-> ReduceButton real; UnstablePercentage live -- the instability model @0x3F0 is
-> byte-decoded and reconstructed, task #66);
+> F6 fixed (ReportLeak -> coolantActive@0x138, binary table [T1]); F14 FIXED
+> (attenuation + the static resonant fc/Q low-pass both baked, c581553);
+> F17 FIXED (CollisionSpeed + ReduceButton real; UnstablePercentage live --
+> the instability model @0x3F0 is byte-decoded and reconstructed, task #66);
 > F8/F21/F22 open (voice budget unhit / attack polish / HRTF option).
+> Post-audit: the footstep cold-start warm-up bug (idle watcher chains +
+> fill-0 smoothers vs the transient drop gate) fixed in a11a697.
 > attrnull = 0: every authored audio attribute binds a real member.