Freeze the bundle: draft → ready, stamps sha256 on the row. Django is a thin proxy here: resolve template refs into the bundle, ask the janitor to seal it (the janitor returns the sha + the spec it derived from the typed resources), then stamp the row. No `transaction.atomic()` — the janitor's freeze is idempotent (on retry it re-reads the existing `.frozen` marker + re-derives spec), so a partial failure here is recoverable by re-calling freeze, not by transactional rollback. Holding an atomic block across the janitor HTTP call previously deadlocked the agent_revision row against the janitor's spec write — that's moved off the janitor side as part of the same fix.