`places a delayed track on its authored start` timed out on the windows runner
and failed an unrelated PR, the second time this week an ffmpeg audio test has
done that.
The previous fix raised the budget in `audioMixer.grouping.test.ts`, which was
the file the symptom named. It was the wrong scope: that file was the only audio
suite with explicit timeouts at all. `audioMixer.level.test.ts` had none, so its
two real-ffmpeg tests ran on vitest's 5s default. The failing one takes ~137ms
locally, so the runner is not 36x slower — but 5s was never a budget anyone
chose for a full mix.
Applied to the suite rather than to each test, so there is one home for it, and
scoped to the ffmpeg-gated describe: the sibling parsing suites are pure and
should keep failing fast at 5s.
Headroom alone would only have delayed an undiagnosable failure. The ffmpeg
process timeout is 5 minutes by default, far above any test budget, so a stalled
mix could only ever surface as a bare "Test timed out" with no stderr and no
failing stage. Tests now cap it at 20s and assert through a helper that reports
`failures` instead of collapsing to `expected false to be true`.
Both claims verified rather than asserted: a deliberately 6s test now passes
where the 5s default would have killed it, and forcing the process timeout to
1ms reports `stage: "prepare", reason: "ffmpeg_timeout"` instead of a timeout.
Reviewing with whitespace ignored is much smaller: adding the third argument to
`describe` reindents the suite body, so 131/101 is really 34/4.