Searchlight + ThermalSight ToggleLamp WIRED (#61) -- and a swapped table attribution ROOT-CAUSED, retracting a false "1995 latent bug"

Both classes' Receiver::MessageHandlerSet were default-constructed blackholes
(input-path audit systemic cause #1): entryCount 0, no parent chain, Find()
returns NullHandler for every id, Receive drops silently.  The new unhandled-
message trace printed it on the first press:

    [btntest] PRESS 0x14 at poll 400
    [msg] UNHANDLED: Searchlight has no handler for message id 3

Each class now has a GetMessageHandlers() function-local static chained to
PowerWatcher's (which name-resolves through HeatWatcher/MechSubsystem to
Receiver's empty ROOT set, so id 3 does NOT collide with HeatSink's
ToggleCooling), plus a correctly-typed forwarder -- Receiver::Handler is
void(const Message*) while the decomp shape is Logical(Message&), so a cast
would be UB that merely happens to work on x86 __thiscall.  DefaultData
re-pointed off the dead empty sets.  MessageArg now reads the NAMED
ReceiverDataMessageOf<int>::dataContents with a static_assert locking it to the
binary's message+0xC (was a raw offset read -- databinding rule).

ROOT CAUSE of a long-standing misattribution: @004b860c is **ThermalSight's**
ToggleLamp (table @0x51120C), NOT Searchlight's.  The two TUs emit parallel
shared-data blocks with identical stride (msg entry, +0x5C attrs, +0x84
Performance triple); what pins each entry to its TU is that "ToggleLamp" is NOT
pooled across them -- two copies exist, each emitted immediately before its own
class-name string ("Searchlight"@0x51144B, "ThermalSight"@0x511475).
[T1: reference/decomp/section_dump.txt:69661-69711]

Searchlight's own handler is @004b838c, which sits in a Ghidra EXPORT GAP (#60).
RECOVERED by raw disassembly of content/BTL4OPT.EXE (scratchpad/dis838c.py, the
EjectAmmo technique) -- and it corrected two things I had inferred wrong:
  * NO ControlsAllowLights/+0x25C novice gate.  Searchlight tests the press
    alone; that lock is ThermalSight-only.  A NOVICE pilot CAN work the lamp.
  * `or word ptr [this+0x18],1` sits AT the jle target -> the graphics-dirty bit
    (updateModel == ForceUpdate(), per #59) is raised UNCONDITIONALLY.

Consequence: the "ORIGINAL 1995 LATENT BUG -- the searchlight can never light"
claim is RETRACTED.  It compared Searchlight's Performance (@004b841c, reads
requestedOn@0x1E0) against ThermalSight's toggle (0x1DC) -- two different
classes -- and so invented a missing 0x1DC->0x1E0 bridge.  Every sibling toggles
the field its own Performance reads.  The searchlight DID light in the arcade,
the searchlight->fog swap was NOT inert there, and building PullFogRenderable is
FAITHFUL rather than a designer-intent deviation (the 2026-07-13 "left as-is"
decision is void; the sim needs no repair).

Verified live, real click seam (BT_BTNTEST):
  0x14 -> [light] requested ON -> reported lightState 0 -> 1     (lamp lights)
  0x12 -> [light] thermal sight requested ON -> thermalActive 0 -> 1
UNHANDLED lines for both classes gone; 40 LNK2019 unchanged (the pre-existing
CreateStreamedSubsystem + Entity__SharedData::DefaultData families only).

Swept the misattribution out of searchlight.cpp/.hpp, thermalsight.cpp/.hpp,
hud.cpp:282 (it had claimed @00511180/@004b838c as HUD's), btplayer.cpp's +0x25C
consumer list, context/{decomp-reference,subsystems,rendering,open-questions,
pod-hardware,experience-levels}.md, docs/{GLASS_COCKPIT,INPUT_PATH_AUDIT}.md.
checkctx.py CLEAN.

Still open (documented, not fixed): ThermalSight has no visible IR effect
(ToggleGlobalThermalVision is a marked no-op, pvision unported, IsLocallyViewed
returns False); ThermalSight publishes "LightState"->0x1D8 where the binary has
"LightOn"->0x1D8 and "LightState"->0x1E0; Searchlight's commandedOn@0x1DC has no
identified role and measured 21 live, hinting our SubsystemResource +0x28 differs
from the binary's.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

game/reconstructed/btplayer.cpp

@@ -1954,7 +1954,9 @@ int BTPlayerRoleLocksAdvanced(void *owner_mech)
 // The player+0x25c "sim live" flag [T1]: 0 only for NOVICE experience.  Binary
 // consumers reached through the owner mech's playerLink (mech+0x190):
 //   * CheckForJam @004bbfcc (projweap.cpp LiveFireEnabled) -- no jam rolls;
-//   * Searchlight::ToggleLamp @004b860c (searchlight.hpp ControlsAllowLights);
+//   * ThermalSight::ToggleLamp @004b860c (thermalsight.hpp ControlsAllowLights)
+//     -- and NOT Searchlight, whose own handler @004b838c has no such gate
+//     (raw disasm, #61: it tests the press only), so novices keep the lamp;
 //   * PoweredSubsystem::HandleMessage @004b0efc short-event path (powersub.cpp).
 // A NULL player (target dummy / unbound dev mech) reads as LIVE so dev rigs
 // keep today's behavior [T3]; the binary derefs unguarded.