An unset INGEST_QUEUE auto-derived "postgres" whenever DATABASE_URL was
PostgreSQL, silently starting the procrastinate ingest worker (schema
migration, reclaim cron, deferred jobs) on every Postgres-backed tenant —
even though none had opted into the api/worker split. Observed on
tenant-blackbox-demo (:0.98.0): ~600 "Deferred 1 job" log lines / 24h.
Resolve an unset INGEST_QUEUE to "memory" (the in-process anyio queue)
regardless of the database backend. procrastinate is now strictly opt-in
via an explicit INGEST_QUEUE=postgres; the existing guard still rejects
postgres against a SQLite DATABASE_URL. Docs + unit test updated.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
