The broker code moved to an append-only hash-chained audit log (actor_member_id / actor_display_name / payload / prev_hash / hash with integer GENERATED ALWAYS AS IDENTITY id) but prod still had the original 0000-migration shape (actor_peer_id / metadata / text id). Every peer_joined / peer_left event logged 'audit log insert failed' — no audit trail captured at all. Applied manually on prod already; committing the migration so future environments converge. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>