* fix(audio): prepend silent preroll so sink-wake does not clip cues
Short catalog tones start in a fresh paplay process while PipeWire is
still waking a suspended sink, so the first tens of milliseconds of the
cue are missing. Prepend 100ms of silence in the same WAV, cache the
result by source path, mtime, and preroll length, and fall back to the
original file if the preroll cannot be built. CI mock players keep the
raw path.
Fixes#800
* fix(audio): cache sink-wake preroll without tempfile.mkstemp
Some tests replace sys.modules["tempfile"] with a MagicMock, so
mkstemp unpacking fails and playback falls back to the raw cue.
Name the cache file from a short sha256 of the source path, mtime,
and preroll length, write a sibling .partial, then os.replace it
into place. Reload real tempfile and wave in the audio feedback
tests so they still pass after those mocks leak.
Fixes#800
* fix(tests): pin real wave for preroll without reloading tempfile
Popping tempfile out of sys.modules in the audio feedback fixture
made preroll tests pass, but later whisper tests then bound
TemporaryDirectory from a MagicMock. Import real tempfile and wave
at module top, pin only wave while audio_feedback is reimported,
and bind TemporaryDirectory from the real stdlib if a sibling test
already replaced tempfile.
Fixes#800
* fix(audio): catch specific preroll errors and type test helpers
The new preroll path swallowed every exception, which hid bugs and
disagreed with AGENTS.md. Catch OSError, ValueError, and wave.Error
on the inner partial cleanup and the outer fallback so a bad WAV or
cache write still falls back to the original cue, and other errors
still propagate. Annotate the two test helpers the same review
flagged.
* fix(audio): fall back when truncated cues raise EOFError
wave.open can raise EOFError on a truncated RIFF before playback.
Catch it with the other preroll failures so start/stop still play the
original file.
Fixes#800
