feat(formats,viewer): movie subtitles, voice decode, and the movie manifest

The movie cutscene subtitle + voice pipeline, driven by the ADVERTISE_MOVIE
manifest (the authoritative movie -> subtitle -> voice index). Also flushes
several sessions of local WIP (async viewer loading, grouped-pool XBG7/hero-ship
decode, drawlog tooling). See docs/HANDOFF-movie-voice-subtitles-2026-07-19.md.

Subtitles (movie_subtitle.rs):
- Full movie->track->text chain; join multi-line captions sharing one timing
  (fixes S13A dropped "Look at it father" line); overlap-safe active_cues();
  Latin-1 accents preserved.

Voice (slb.rs): XACT .slb -> XMA1 RIFF; take the FIRST sub-wave bounded by its
declared data size (fixes S10-S16 alternate-take garble); list_voice_clips.

Manifest (movie_manifest.rs): parse ADVERTISE_MOVIE (0x5B983A08) for the real
movie->voice binding (not always VOICE_<movie>; e.g. hokyu -> VOICE_D_* in etc\).
Resolve the token's sound.pak path via sounds.tbl. DIRECT bindings only — the
demo-id shared-clip fallback for unbound hokyu movies was verified WRONG in-game
and reverted (unbound hokyu stay unvoiced; correct join key is an OPEN problem).

Viewer: manifest-driven voice (movie player toggle + solo button), standalone
"Voice Lines" browser, stacked caption overlay.

Tests: 46 formats-lib + 11 viewer-lib + movie_manifest/movie_subtitle/slb disc
tests; full workspace green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

crates/sylpheed-viewer/src/lib.rs

@@ -72,9 +72,28 @@ pub fn run() {
 }
 
 fn setup_scene(mut commands: Commands) {
-    commands.spawn(DirectionalLight {
-        illuminance: 10_000.0,
-        shadows_enabled: true,
-        ..default()
+    // Bright ambient so surfaces facing away from every light aren't pure black.
+    commands.insert_resource(AmbientLight {
+        color: Color::srgb(0.9, 0.93, 1.0),
+        brightness: 900.0,
     });
+    // A multi-directional rig (key + fills + rim + underside) so an orbiting
+    // camera always has some light on the visible side — the single front light
+    // left the backside unreadable.
+    let lights = [
+        (Vec3::new(1.0, 2.0, 1.5), 10_000.0, true),  // key: front-top-right
+        (Vec3::new(-2.0, 1.0, 0.5), 4_500.0, false), // fill: left
+        (Vec3::new(0.5, 0.8, -2.0), 6_000.0, false), // rim: behind
+        (Vec3::new(0.0, -1.5, 0.5), 2_500.0, false), // underside fill
+    ];
+    for (from, lux, shadows) in lights {
+        commands.spawn((
+            DirectionalLight {
+                illuminance: lux,
+                shadows_enabled: shadows,
+                ..default()
+            },
+            Transform::from_translation(from).looking_at(Vec3::ZERO, Vec3::Y),
+        ));
+    }
 }