admin: add backup/restore flow and structured request logging

README.md

@@ -14,6 +14,8 @@ Dark dashboard for Arr* services and custom links.
 - Icon blobs stored in the database
 - Containerized app deployment (requires MariaDB)
 - Admin-managed service links
+- Admin backup/export and restore with dry-run validation
+- Structured JSON logs with request IDs (`x-request-id`)
 
 ## Local Dev
 
@@ -59,6 +61,12 @@ The app expects a MariaDB instance configured through environment variables.
 - `USERNAME_MAX_LEN` (default: `64`)
 - `PASSWORD_MIN_LEN` (default: `12`)
 
+### Backup / Restore API
+
+- `GET /api/admin/backup` exports users and links as JSON
+- `POST /api/admin/restore?dry_run=true` validates a backup payload without applying
+- `POST /api/admin/restore?dry_run=false` applies restore when body includes `"confirm": true`
+
 ## Gitea CI/CD
 
 Add these secrets in Gitea: