Searchlight reconstruction -- the pod's night kit, both halves

The subsystem (sim/toggle/attribute/replication) was already complete; this
lands the missing VISUALS, decoded from MakeMechRenderables @004cef28 case
0xbd8 (raw pseudocode part_014):

- COCKPIT: the 1995 searchlight is a FOG SWAP -- the @00456778/@00456814
  watcher switches DPLRenderer::SetFogStyle between the authored fog= (lit)
  and nosearchlightfog= (dark) sets per map/time page in BTDPL.INI.  The
  engine kept the whole system under its real names; completed the stubbed
  plane application (currentFogNear/Far) and transcribed the watcher (with
  its inverted-cache seed) into TickSearchlight.  CONSEQUENCE: night now
  STARTS on the authentic dark set (near-plane 5u on arena pages) -- our
  builds had rendered the searchlight-ON fog permanently.
- EXTERNAL: spot.bgf beam cone hung on the searchlight SITE joint, shown/
  hidden from the replicated LightOn attribute (@0045612c watcher).  Site
  segments now build geometry-less DCS children (posed + parentable, as the
  1995 graph did) -- previously they were skipped entirely.
- searchlight.hpp: commandedOn @0x1DC identified as mountSegment (resource
  segmentIndex; the cone's mount joint).

Benches: searchfog.sh (solo cockpit: first-tick dark sync, F5/0x14 press ->
SetFogStyle(2), red-fog probe end-to-end), spotcone.sh (2-node: B's button ->
lightState replication -> A logs "[spot] cone SHOWN (seg 20)").  Cone look
(size/aim on the mount) pending an eyeball pass.

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

scratchpad/night12/searchfog.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+# SEARCHLIGHT bench 1 (cockpit fog swap): solo night run; BT_BTNTEST presses
+# the searchlight button (0x14 = F5's binding) at poll 600, releases 700.
+# PASS (log): "[spot] searchlight pass: N light(s) ... (cockpit: fog watcher)";
+# first tick "[spot] cockpit fog -> searchLightOff" (the inverted-seed sync ->
+# authentic DARK night start on nosearchlightfog=5..400); after the press
+# "[light] ... requested ON", "[fogstyle] SetFogStyle(2)", "[spot] cockpit fog
+# -> searchLightOn".  BT_SHOT frames: post-toggle frames measurably brighter
+# (fog near 5 -> 40 on arena_night-family pages).
+set -e
+cd /c/git/bt411/content
+. /c/git/bt411/scratchpad/night6/bench_common.sh
+taskkill //F //IM btl4.exe > /dev/null 2>&1 || true; sleep 2
+rm -f sfog_*.png sfog.log
+sed "s/^map=.*/map=grass/; s/^time=.*/time=night/; 0,/^vehicle=.*/s//vehicle=madcat/" MP.EGG > SG2.EGG
+
+(
+  export BT_START_INSIDE=1 BT_SHOT_EVERY=60 BT_SHOT_PREFIX=sfog
+  export BT_BTNTEST=0x14,600,700
+  export BT_FIRE_LOG=1 BT_FOG_LOG=1 BT_DEV_GAUGES=1
+  bt_launch "sfog.log" SG2.EGG 0x03
+)
+sleep 75
+taskkill //F //IM btl4.exe > /dev/null 2>&1 || true; sleep 3
+
+echo "=== searchlight pass + fog receipts:"
+grep -aE "\[spot\]|\[fogstyle\]|\[light\]|btntest" sfog.log | head -16
+echo "=== fog page resolve:"
+grep -a "\[fog\] resolved" sfog.log | head -2
+echo "=== frames:"
+ls sfog_*.png 2>/dev/null | head -20

scratchpad/night12/spotcone.sh

@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+# SEARCHLIGHT bench 2 (external spot cone + replication): night 2-node.
+# A walks to 40u of B and stands (facing B).  B presses the searchlight button
+# (BT_BTNTEST 0x14) at poll 300.  B's lightState replicates (subsystem record
+# 0x14) -> A's replicant Searchlight LightOn flips -> A's TickSearchlight shows
+# the spot.bgf cone on B's mech.
+# PASS: A log "[spot] searchlight pass: ... (external: spot cone)" for B's mech
+# + "[spot] cone SHOWN (seg N)" after B's press; A BT_SHOT frames brighten near
+# B post-toggle.  B log: "[light] ... requested ON" + lightState 0 -> 1.
+set -x
+. /c/git/bt411/scratchpad/night6/bench_common.sh
+cd /c/git/bt411/content || exit 1
+bt_assert_player_env
+taskkill //F //IM btl4.exe > /dev/null 2>&1
+sleep 2
+rm -f cone_a.log cone_b.log cone_relay.log coneA_*.png
+bt_expert_egg MP.EGG SG3.EGG
+sed -i "s/^map=.*/map=grass/; s/^time=.*/time=night/; s/^vehicle=.*/vehicle=madcat/" SG3.EGG
+
+(
+  export BT_BTNTEST=0x14,900,960
+  export BT_FIRE_LOG=1 BT_FOG_LOG=1 BT_DEATH_LOG=1 BT_MP_LOG=1
+  bt_launch cone_b.log SG3.EGG 0x0C -net 1601
+)
+sleep 2
+(
+  export BT_GOTO=enemy BT_GOTO_STOP=40 BT_KEY_NOFOCUS=1
+  export BT_SHOT_EVERY=60 BT_SHOT_PREFIX=coneA
+  export BT_FIRE_LOG=1 BT_FOG_LOG=1 BT_MP_LOG=1
+  bt_launch cone_a.log SG3.EGG 0x03 -net 1501
+)
+sleep 5
+python ../tools/btconsole.py SG3.EGG 127.0.0.1:1501 127.0.0.1:1601 > cone_relay.log 2>&1 &
+RELAY=$!
+sleep 90
+kill $RELAY 2>/dev/null
+taskkill //F //IM btl4.exe > /dev/null 2>&1
+sleep 3
+echo "=== B (lamp owner):"
+grep -aE "\[light\]|btntest|\[spot\]" cone_b.log | head -8
+echo "=== A (observer -- cone events):"
+grep -aE "\[spot\]" cone_a.log | head -8