FilmCraft's MPEG audio Layer I/II decoder as `craft_audio::mpa` behind
`mpa-decode`, kept over symphonia's: the same quality where both
decode, and it also decodes the MP2 files ffmpeg writes by default
(mono at 384 kbit/s), which symphonia rejects. `TrackDecoder` and the
native read path take MP1/MP2 in MP4, Matroska and raw streams;
symphonia keeps MP3 only, so its `mp1` and `mp2` features are dropped.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Dylan M. Taylor <dylan@dylanmtaylor.com>
