-- The on-site admin chooses where encrypted DB backups are written (a mounted USB/SATA/
-- SMB/NFS path), from the Backup screen — not a server env var. Additive, nullable ALTER:
-- null = not configured (backups stay a no-op). The BACKUP_KEY stays an env/Komodo secret
-- (a key must NEVER live in the DB it backs up). See wiki/concepts/backup-recovery.md.
ALTER TABLE `site_config` ADD `backup_target_dir` text;