The RUDP document server sent a host sink's refusal as an untyped Error (code None).
It now sends write_not_authorized with details naming the record, as C#, TS and
Python do; the text stays the fixed variant text, never the sink's. The rejection
carries the put's record_key. Other rejections stay untyped. Unit test pins the
bytes to the error-vectors.json write_not_authorized vector; integration tests
check code/details on the wire and that a refused put reaches no sink.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>