Migration 057 inserts 6 AD script templates with NULL team_id and NULL
created_by. Neither backfill path (created_by→users, team_id→team admin)
could attribute them to an account, causing the verify check to fail.
Fix: pre-create the platform sentinel account (ON CONFLICT DO NOTHING,
safe since 3a40fe11b427 also creates it idempotently) and add a final
fallback UPDATE assigning any remaining NULL script_templates to it.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>