Replace route-local restore writes with the core transaction and map preflight, rollback, and post-commit cleanup failures to precise HTTP responses. Treat only ENOENT as a missing export file and return transaction, restored, skipped, migrated, and restart facts.
Update the settings panel to describe the full sensitive configuration group, avoid restart guidance for empty plans, and reload settings after both successful and failed imports so the UI reflects committed disk state. Add HTTP regression coverage for export and restore error semantics.