Create a single facility credentialing workflow

Creates a new facility credentialing workflow for one facility and immediately hydrates it with facility data from upstream systems. When to use: Use this to onboard an individual facility into the credentialing process. For multiple facilities at once, use POST /facility-credentialing-workflows/v2/bulk-create (preferred) or POST /facility-credentialing-workflows/bulk-create. Preconditions: The facility identified by certifyFacilityId in the request body must already exist in the system. Only one active workflow per facility is allowed — if an active workflow exists, a 409 Conflict is returned. Returns: 201 Created with the full, hydrated GetFacilityCredentialingWorkflowResponse in the body, including facility data populated from upstream. On business-rule violations (e.g., invalid facility state), a 422 Unprocessable Entity is returned.