Another dependency the app should not be asking the platform for:
- audio_decode — MP3 (layer 3, LSF tables, synthesis) and Ogg Vorbis
(codebooks, floor, residue, MDCT) decoders, with tag reading. Both are
checked against oracle fixtures rather than against our own expectations.
- audio_encode — an Ogg Vorbis encoder: MDCT, psychoacoustics, floor and
Huffman coding, setup tables, plus `oggenc` and `audiobench` binaries.
- audio_picture — waveform and spectrogram rendering, and compositing.
- audio_lyrics — word-level lyric alignment (DTW plus a DP snap) and the
baked schema behind karaoke timing.
- audio_sidechannels — the side-channel plumbing between them.
libs/voice grows a CUDA backend and an alignment path beside its CPU decoder,
with a `whisper_parity` binary to keep the two honest.
