T654 asked to build backend/api/critical/backup-status-api.php (action=get_backup_status, backup dir scanner for a dashboard tile). Confirmed this already exists and works: T739 (closed 08/05/26) added it to BACKUP-REG.md's registry after confirming it live. Re-verified independently this session (10:37am PT): GET action=get_backup_status returns real data -- status:ok, per-group health (platform-commands: CRITICAL, 256 files, last_backup 08/05/26, age_hours 475, health:stale -- a legitimate stale flag, not an error). The build task itself is done; the 'stale' finding is separate follow-up work (routine backup cadence), not part of this build task's scope.