Harden mux + decrypt paths; fail-loud on unresolvable keys

mp4 demuxer (untrusted input): bound every allocation sized from a box
field (stsz/stco/stsc counts, stts/ctts run-lengths, per-sample and moov
sizes, plus an absolute cap so a sparse file can't inflate file_len);
guard the parse_stsd slice and a zero mdhd timescale; cap track count so
the per-track PID can't overflow; rewrite read_moov to handle size==0 /
size<8 / 64-bit largesize; parse esds/AudioSpecificConfig for AAC; write
tkhd duration in the movie timescale.

decrypt: resolve_mux_key_map now fails loud on an extent no key can
classify instead of inheriting the previous extent's key, so a keymap
never silently carries a wrong key; the sweep/patch key-fetch recovery
fails loud when a unit is still unresolved after the retry.

AACS: reject inverted forensic segments in both range builders; compare
the forensic index in u16 space so an out-of-range value can't truncate
onto a valid u8 index. RECOVERED_ERROR no longer latches the damage zone,
preserving the 30s wedge cooldown for a following hard error.

audio: AAC/MP2/MP3/FLAC carry the last PTS across a PES with no timestamp;
the DTS-HD extension-sync search is bounded to after the core; the MP4
16.16 sample-rate field saturates. demux_sink records the video reference
before the kind filter so audio:// / sub:// keep multi-clip PTS continuity
and the DELAY tag.

Remove a dead error variant and the AACS-unsupported-video code; codec
comments cite the primary format specs; assorted doc/naming fixes and
regression tests throughout.

src/disc/mod.rs

@@ -1867,7 +1867,7 @@ impl Disc {
         capacity: u32,
         handshake: Option<HandshakeResult>,
         handshake_error: Option<Error>,
-        _opts: &ScanOptions,
+        opts: &ScanOptions,
         udf_fs: udf::UdfFs,
     ) -> Result<Self> {
         let scan_with_t0 = std::time::Instant::now();
@@ -1931,7 +1931,7 @@ impl Disc {
         // forced flags match what the muxer derives during a rip (both use the
         // one shared PGS classifier); the rip path leaves it off — the muxer
         // detects forced while muxing, without a second read of the clip.
-        if _opts.probe_forced_subtitles {
+        if opts.probe_forced_subtitles {
             for title in &mut titles {
                 if title.content_format == ContentFormat::BdTs {
                     pgs_forced_probe::probe_and_set_forced(reader, title);
@@ -2277,8 +2277,8 @@ impl std::fmt::Debug for Key {
 ///      next candidate (and ultimately surfaces a key error rather than silently
 ///      writing ciphertext).
 ///
-/// Reuses the ecosystem's single `ts_sync_destroyed` predicate and the full
-/// (bus + AACS) unit decrypt, so it agrees with the actual mux decrypt.
+/// Reuses the ecosystem's single `is_clean` content-clarity predicate and the
+/// full (bus + AACS) unit decrypt, so it agrees with the actual mux decrypt.
 fn aligned_unit_keys_validate(
     unit_keys: &[(u32, [u8; 16])],
     read_data_key: Option<&[u8; 16]>,
@@ -2367,7 +2367,7 @@ impl Disc {
     /// else (UDF filesystem, BDMV nav, PLAYLIST/CLIPINF) is always clear.
     ///
     /// The in-read decrypt-verify gate (`DecryptingSectorSource`) uses this so it
-    /// never consults [`ts_sync_destroyed`](crate::aacs::content::ts_sync_destroyed) about
+    /// never consults the TS-sync content check about
     /// non-content bytes — filesystem data has no TS sync and would otherwise be
     /// mistaken for ciphertext (the first-2-GB false-positive this fixes).
     ///