Regex matches an empty string


`type`	`https://docs.frem.sh/reference/api/errors/regex-matches-empty`
HTTP status	`400` Bad Request

What it means

The custom pattern matches an empty string, so it would match everywhere.

Make at least one part of the pattern mandatory, for example a fixed prefix.

All fremforge API errors are RFC 9457 problem+json:

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

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