- Add db-backup service to compose.yaml (postgres:17-alpine + cron)
- Add pgbackups volume for backup storage
- Add scripts/restore.sh for manual restore from latest backup
- Update .env.example with BACKUP_RETENTION_DAYS and BACKUP_VOLUME_NAME
- Document backup/restore flow in README
Bump version -> 1.15.0
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
