Queue -> StartTranscribing -> ffmpeg to 16 kHz WAV -> gateway chain ->
CompleteUpload, with a per-job timeout so a hung endpoint ends in failed, not
a spinner. The upload and the WAV are deleted on every path (audio is never
retained). A shutdown mid-job is not a failure: the row is left for the
start-up sweep. Cancellation wins over a non-empty queue, so queued jobs are
never started on shutdown; stop() deletes their audio and refuses new jobs.
Concurrency is 1 on purpose: two simultaneous long jobs on iguana were never
measured, and a Metal OOM there latches whisper (infra#273). The queue is
process-local, so ADR-018's single-replica assumption now has a second
dependent.
Mutation-checked, -race clean: cleanup, shutdown-vs-failure, timeout,
concurrency and stop-cleanup each turn a test red.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
mathiasandClaude Sonnet 5.5