KB: EXPERIENCE LEVELS decoded -- the 0x25c block is the simulation-mode flags

The egg's per-pilot 'experience' (novice/standard/veteran/expert) is the
pod's simulation-fidelity tier -- stored at BTMission+0xe4 and seeded into
the BTPlayer ctor's flag block @4c0bc8 [T1].  The old 'per-role display
toggles / returnFromDeath' reading was WRONG: the source is
mission->experienceLevel, and the neighboring pair copies
mission->advancedDamageOn (the egg's technician splash/collision switch),
not role floats.  Known consumers: 0x260 = the HEAT-MODEL master switch
(FUN_004ad7d4), 0x25c = the novice sim-lockout (jams/searchlight/powersub),
0x274 = the raw level (FUN_004ac9c8 ==0 novice predicate).

NEW established topic context/experience-levels.md (data path, binary flag
rows per level, manual cross-refs, corrections log) + router row; sweeps in
decomp-reference/gauges-hud/open-questions/pod-hardware/subsystems.
btplayer.cpp/.hpp re-annotated with the corrected semantics; the guarded
role-based seeding stays as a marked [T3] stand-in (slot drift vs the
binary switch documented inline) until the wiring task points it at
BTMission::ExperienceLevel().

(Research by the parallel context session; committed from the glass line.)

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

context/subsystems.md

@@ -57,8 +57,8 @@ Making a base byte-exact GROWS every subclass — they must be re-based TOGETHER
 - **✅ DONE (task #7, `afefaee`)** — SubsystemMessageManager 0xBD3 (a
   **damage/explosion consolidation hub** cached to `Mech[0x10d]`=0x434; the factory builds the REAL
   class and `mech.hpp` names the slot `messageManager` — the old `controlsMapper` mislabel is swept,
-  the real mapper is roster slot 0. NOT the valve/advanced-damage gate — that's the owning **BTPlayer**
-  @mech+0x190, see [[combat-damage]]/[[open-questions]]). [T2]
+  the real mapper is roster slot 0. NOT the valve/heat-model gate — that's the owning **BTPlayer**
+  @mech+0x190 carrying the EXPERIENCE-level flags, see [[experience-levels]]). [T2]
 
 ## The watcher electrical chain (task #57, 2026-07-13 — the torso power gate)
 The Watcher branch is POWERED indirectly: a watcher WATCHES another roster subsystem and mirrors