Unsupported grant type


`type`	`https://docs.frem.sh/reference/api/errors/unsupported-grant-type`
HTTP status	`400` Bad Request

What it means

The request was malformed, or a field failed validation.

Example detail messages returned with this error:

Only client_credentials is supported at this token endpoint. POST to https://frem.sh/api/v1/oauth/token with grant_type=client_credentials.

All fremforge API errors are RFC 9457 problem+json:

{
  "type": "https://docs.frem.sh/reference/api/errors/unsupported-grant-type",
  "title": "Bad Request",
  "status": 400,
  "detail": "..."
}

Branch on type, not on title or detail - those are human-readable and may be reworded.