-- Migration 020: where an upload job is, and whether the service is still reporting (ADR-035).
--
-- progress    the job's ordered phases as JSON (key, label, state, times, done/total).
-- progress_at when a phase last REALLY changed or advanced.
-- alive_at    a heartbeat stamped every few seconds by a goroutine independent of any
--             engine call. The two differ on purpose: alive says the service is still
--             reporting, progress says work is moving, and a page that cannot tell a
--             crashed service from a slow model is the failure this exists to end.
--
-- All three are NULL until the job starts. They sit on the already-FORCE'd, RLS-scoped
-- uploaded_transcripts, so the exact-set isolation test is unaffected.
ALTER TABLE uploaded_transcripts
    ADD COLUMN progress    JSONB,
    ADD COLUMN progress_at TIMESTAMPTZ,
    ADD COLUMN alive_at    TIMESTAMPTZ;