* feat(playback): stream buffering UI, ranged M4A tail prefetch, demuxer fix
Defer seekbar/progress until HTTP stream is armed for both legacy and
RangedHttpSource; show buffering overlay on cover art. Add MP4 tail
prefetch and Symphonia isomp4 bounded-mdat/moov-at-EOF probing so
moov-at-end M4A can start without reading the full mdat.
* feat(hot-cache): spill large ranged streams to disk for promote
When a ranged HTTP download completes above the 64 MiB RAM promote cap,
write the existing buffer once to app-data stream-spill/ and register it
for hot-cache promote (rename) and replay via fetch_data. Analysis seeds
from the spill file up to the local-file cap (512 MiB).
* fix(ui): stream buffering — grayscale cover and static clock icon
Desaturate player and queue cover art while isPlaybackBuffering; keep a
non-animated clock overlay for visibility without the spinning animation.
* fix(playback): review follow-up — tests, i18n, spill cleanup, changelog
Clippy and test layout fixes; stream spill orphan cleanup on startup;
buffering flag guard in progress handler; bufferingStream in all player
locales; CHANGELOG and contributor credits for stream/M4A work.
* docs: attribute stream buffering and M4A streaming to PR #737
* test(audio): avoid create_engine in stream spill unit test
CI runners have no audio output device; test spill take/consume via
the Mutex slot only, matching install_stream_completed_spill tests.
The high-frequency PlaybackProgressSnapshot channel — type, mutable
snapshot, listener Set, emit/get/subscribe — moves into a dedicated
src/store/playbackProgress.ts. playerStore re-exports the public 3
(getPlaybackProgressSnapshot, subscribePlaybackProgress, the type) so
the 5+ external callers (PlayerBar, FullscreenPlayer, WaveformSeek,
LyricsPane, MobilePlayerView, TauriEventBridge) keep their existing
imports.
Direct unit tests pin the delta short-circuit (`currentTime <0.005`,
`progress/buffered <0.0002`) that keeps idle CPU bounded. The
end-to-end Tauri-event drive path remains covered by the existing
playerStore.progress characterization test (unchanged).
playerStore 3516 → 3490 LOC.
cucadmuh
Frank Stellmacher