Retrieve the latest PSV PDF path for a facility workflow

Returns the path to the most recently generated PSV PDF document for the specified facility credentialing workflow, or indicates that generation is still in progress. When to use: Call after POST /facility-credentialing-workflows/{id}/generate-psv to retrieve the completed document. "Latest" is determined by the most recent PSV-related timeline event. Returns: * 200 OK — body contains { workflowId, psvPdfPath }. * 202 Accepted — body contains { workflowId, status: "GENERATING" }, meaning PDF generation is still in progress. Poll this endpoint again until 200 OK is returned.