v2.6.0

• live playback speed — a.playbackRate settable mid-playback, smooth tape-style ramp (player + worker)
• audio(src, { worker: true }) — worker-hosted engine from the main entry
• sliding stretch — stretch(t => f) / stretch({ t, v }): continuous tempo envelope, pitch preserved
• shrink(gap?) — compress silent pauses to a target gap ≡ ffmpeg silenceremove, audacity truncate-silence
• crossover(...freqs) — LR4 band split, allpass-flat sum ≡ ffmpeg acrossover
• adjustable fade — fade(dur, { start, end, mid }): arbitrary levels, midpoint skew
• per-block note events for streaming instruments; contract frames hook for length-changing plugins
• registry 125 → 136: chroma/tonnetz stats, stretch-* ×9 (pvoc-lock/pghi/wsola/psola/sms/transient/hybrid/paul)
• CLI: split --cue album.cue — cue-sheet tracks, {title} naming, tags; [ ] player speed keys
• save/encode: empty range fails before touching the file (#27)
• fix: unranged mix/write restarted at every block (source tiled)
• decode: dual-mono wav/flac keep both channels; browser falls back to native WebAudio for unbundled codecs
• OPFS budget auto-detects via storage.estimate()
• audio.d.ts for every @audio/* plugin package, generated from manifest metadata
• audio.plugins registry (audio.atoms stays as deprecated alias)

Full Changelog: v2.5.1...v2.6.0