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-formats/src/pak.rs

@@ -178,6 +178,18 @@ impl PakArchive {
         })
     }
 
+    /// Parse **only** the TOC from a `.pak` index, without any segment data.
+    ///
+    /// For huge archives (`sound.pak` is ~1 GB across `.p00..p04`) this lets a
+    /// caller locate one entry's `(offset, size)` and read just that byte range
+    /// from the segments, instead of loading the whole thing into memory. The
+    /// returned entries are sorted by `name_hash` (binary-searchable).
+    pub fn parse_toc(index: &[u8]) -> Result<Vec<PakEntry>, PakError> {
+        // Reuse from_parts' validation with an empty data blob; the entries are
+        // independent of the data.
+        Ok(Self::from_parts(index, Vec::new())?.entries)
+    }
+
     /// All TOC entries, in stored order (ascending `name_hash`).
     pub fn entries(&self) -> &[PakEntry] {
         &self.entries