feat: add restore drill coverage

Add restore verification and image-storage recovery scripts, update deployment documentation, and note the restore drill milestone in the implementation status.

docs/DEPLOYMENT.md

@@ -132,12 +132,30 @@ BACKUP_FILE=/secure/backups/inventory-20260909T000000Z.dump \
 This checks that the file is a readable PostgreSQL custom-format archive without
 changing any database.
 
+Restore a database dump during a scheduled window:
+
+```sh
+BACKUP_FILE=/secure/backups/inventory-20260909T000000Z.dump \
+POSTGRES_DB=inventory \
+POSTGRES_USER=inventory \
+POSTGRES_PASSWORD='use-secret-storage' \
+./scripts/restore-postgres.sh
+```
+
+Restore image storage snapshots using the preserved NAS backup:
+
+```sh
+IMAGE_STORAGE_SOURCE=/secure/backups/pokemon-inventory-images \
+IMAGE_STORAGE_DESTINATION=/var/lib/pokemon-inventory/images \
+./scripts/restore-image-storage.sh
+```
+
 Back up image storage and the deployment `.env` through the NAS secret/backup
 system as well. Never commit either one. Before upgrading, record the current
 image tags and database migration state. To roll back, stop the application
 services, restore the previous image tags, restore the database dump if the
-schema changed, then start the stack and verify `/health` and a read-only
-catalog request.
+schema changed, then restore the image snapshot and verify `/health` and a
+read-only catalog request.
 
 ## Reverse proxy