Run a Death Master File check for a practitioner

Calls the downstream Death Master File (DMF) deceased-provider check service with the supplied SSN and date of birth. Use this endpoint to verify that the DMF integration is reachable and functioning; it is intended primarily as a diagnostic or administrative tool rather than a routine production call. Both ssn (9-digit string) and dateOfBirth (format yyyy-MM-dd) are required. Returns the raw DMF check result on 200. Returns 502 when the downstream DMF service is unavailable or returns an error.