Stop naming specific commercial discs in comments and tests

Fifteen references across six files named the discs a defect was first
seen on. The parser leak found earlier was not an isolated slip — the
same habit runs through the mux comments, the changelog and the AACS
content verdict, where a title name was standing in for the shape of
the problem.

Every one is replaced with the property that actually mattered: a
multi-clip title, a UHD Dolby Vision profile 7 dual-layer stream, a
disc carrying an authored-bad TS packet. The comments are more useful
for it — the reader needs to recognise the shape on a disc they have,
not the one we happened to have.

`SEG_MainFeature` stays: the parser matches on that literal, so it is
a format token rather than a title.

src/mux/mkv.rs

@@ -1373,7 +1373,7 @@ impl<W: Write + Seek> MkvMuxer<W> {
         // with the base layer's. The two video PTS sequences overlap, so the EL's
         // frames look like multi-second backward jumps against the base layer's
         // frontier and would false-trigger an epoch reset on every GOP (the exact
-        // ratchet that inflated Top Gun's 1-clip timeline to ~7 h). Only the base
+        // ratchet that inflated a 1-clip timeline to ~7 h). Only the base
         // video layer establishes/advances the frontier and opens epochs; the EL
         // — like audio and subtitles — rides the current offset.
         let drives_epoch = Some(track_idx) == self.primary_video_track;