Backup export/import now covers Role, User, RolePermission, Notification, AuditLog and Document (with actual file content), not just business data - matching "wirklich alle Daten". Role/User use natural keys (role.key, resource+action) so a bundle restores cleanly into a different database. Adds BackupSchedulerService (@nestjs/schedule) for cron-based automatic backups to a local path (BACKUP_STORAGE_PATH), with retention pruning and a file-mtime guard against duplicate runs across replicas. New GET /backup/schedule and POST /backup/schedule/run-now endpoints, plus a status card and manual trigger in the frontend Backup settings page.