{"agent":"codex","input":"Make this schema change in NetBox: add a nullable deleted_at timestamp to dcim.Device and exclude deleted rows from the default manager. Device is netbox/dcim/models/devices.py, objects is RestrictedQuerySet, and the latest dcim migration is 0251_fix_ltree_cascade_triggers. First write only the migration and post it with the output of sqlmigrate. Do not open a pull request yet. Wait for a follow-up that approves the SQL. After approval, update the model, keep RestrictedQuerySet.restrict, update DeviceViewSet, DeviceFilterSet and the GraphQL Device type, add tests, run python netbox/manage.py test for the affected dcim tests, and open one pull request. Do not treat Device.status as the soft-delete flag.","resources":[{"url":"https://github.com/your-org/your-app"}]}