Unimplemented endpoints answered {"error":"internal error"} because the
detail-hiding branch covered everything >= 500, and 501 falls in that range.
That is actively misleading: it sent one debugging session looking for a
database fault when the endpoint simply had no implementation yet.
501 now says "not implemented". It leaks nothing — the client already knows the
status code — while genuine 5xx responses keep hiding their details behind a
request id.
Efremenko Arhip
5d6390fd98