Implement native-backed SC0000 SFX lifecycle

tools/age_opcodes_himegari.py

@@ -9,7 +9,11 @@ INFERRED: dict[int, dict] = {
     0x7c: dict(name='coroutine-resume', category='control', noop=False, confidence='high', source='investigation', summary='() — scene-coroutine RESUME point. Native requires run-state bit 0x2000000 (ctx[0x6dbc8]) set — THROWS (__CxxThrowException) if unset, so it is only ever reached on a scheduler-driven re-entry, NEVER on a cold first pass (cold flow jmps over it). Restores PC=ctx[0x53d28]+ctx[0x6dbcc]*4, clears the run-bit (ctx+0xa0ce4 &= ~0x2000000), resets input/line state. SC0000 0x443 (falls into the main loop label_444). See engine-re.md §Scene-coroutine framework.'),
     0x90: dict(name='hotspot-branch', category='input', noop=True, confidence='high', source='investigation', summary='cursor/input hotspot hit-test: rect (x,y,w,h) -> 3-way branch on interaction, else fall through to pc+1'),
     0x97: dict(name='hotspot-reg?', category='input', noop=True, confidence='med', source='inference', summary='companion register-hotspot / set-widget-action (argc5: v1 v2 1 1 <action-id>; NO code targets)'),
-    0xb6: dict(name='snd-ctrl?', category='audio', noop=False, confidence='low', source='inference', summary='1 imm; self-chains, 0x41D family near play-sound-effect/0xb5 — sound channel/volume/stop control'),
+    0xb4: dict(name='sfx-load', category='audio', noop=False, confidence='high', source='investigation', summary="(resource_id)(channel) — synchronously resolve/open the scene-manifest asset and replace the channel's decoded sound buffer without starting playback. Native manager supports channels 0..12; SC0000 uses 0..9."),
+    0xb5: dict(name='sfx-start', category='audio', noop=False, confidence='high', source='investigation', summary='(channel) — start the already-loaded channel once (logical loop=false). DirectSound publishes synchronously through Play(0,0,DSBPLAY_LOOPING); the low-level flag loops only the streaming ring, while decoder EOF stops logical playback.'),
+    0xb6: dict(name='sfx-release', category='audio', noop=False, confidence='high', source='investigation', summary='(channel) - stop/destroy the channel decoder and DirectSound buffer, clear its retained resource id, and leave the slot empty. Idempotent for an unused channel.'),
+    0xc2: dict(name='fade-bgm', category='audio', noop=False, confidence='high', source='investigation', summary='(target_percent)(duration_ms) — block script service while linearly fading current BGM volume to 0..100%. Durations >=1000 ms use 100 steps; shorter fades use 10. Target 0 releases the current BGM source at completion.'),
+    0xd9: dict(name='clear-run-state-0x1000', category='control', noop=True, confidence='high', source='investigation', summary='Clear native run/service bit 0x1000; if the secondary context is active, clear the same bit there. SC0000 executes it once after the initial SFX-channel reset, with no VM-visible result.'),
     0x140: dict(name='coroutine-label-yield', category='control', noop=False, confidence='med', source='investigation', summary="(out)(name_str)(sub_str)(in) — scene-coroutine LOOP ITERATOR / labeled yield. Handler copies name/sub strings + the int operand and calls the NATIVE video/transition service (*DAT_005c6018)(8, ctx[0x54fe8], &{name,sub,in}); writes the returned PC-like value to operand 1. In SC0000 label_462 'ループ開始' (@0x46d): `out=G[0x6be]=LABEL('J',G[0x6be])`; loop runs the intro-setup body (incl. call label_125bd = slot-table fill G[0x3239..0x324e]=4..11) and jmps back until out==G[0x6c3] (a per-scene exit-PC immediate) → mov aba5c 0 → content. The gate G[0xaba5c]==1 that opens this loop is NATIVE scene-entry state (no script sets it to 1). DAT_005c6018 is runtime-resolved (all xrefs READ) = SAME class as the DirectDraw workers we don't model. PORT = HOST-MODEL IMPLEMENTED: synthesize the ADV scene-entry gate, run the LABEL/J setup body once, then return the structurally discovered per-scene terminal; do not emulate the video service. See engine-re.md §Scene-coroutine framework."),
     0x1bc: dict(name='block-mark', category='marker', noop=True, confidence='high', source='inference', summary='zero-arg; follows jcc/mov, precedes mov/ret — block boundary'),
     0x1bf: dict(name='call-end', category='marker', noop=True, confidence='med', source='inference', summary='zero-arg; call->0x1bf->stmt-end — end-of-call-statement marker'),