The speaker button in the player bar toggled volume to 0 (or back to
the pre-mute level) but exposed no `data-tooltip`, so hovering it
showed nothing — users couldn't tell what the icon did. Add a tooltip
that switches between "Mute" and "Unmute" with the current state, and
mirror the same string on `aria-label` for screen readers. New
`player.mute` / `player.unmute` keys land across all 9 locales.
* 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.
Each src/locales/<lang>.ts (~1800 LOC) becomes a folder src/locales/<lang>/
with one module per i18n namespace (44 each) plus an index.ts barrel that
reassembles <lang>Translation in the original key order.
Mechanical, script-driven split with a JSON round-trip check: every
locale object is byte-identical to its pre-split form. i18n.ts is
unchanged — './locales/<lang>' now resolves to the folder index.
The per-namespace settings.ts files land ~440-460 LOC; a single i18n
namespace is the natural, non-arbitrary split unit for a flat string
table, so they are intentionally left whole.