When an Anthropic model declines to answer, the Messages API returns
HTTP 200 with `stop_reason: "refusal"` and empty `content`. The
translate mode mapped that to a normal reply with no content, so the
OpenAI-compatible response looked like a successful completion
(`finish_reason: "stop"`, empty message). Routers, agents and UIs could
not tell "the model declined" from "the model had nothing to say", and
no fallback was triggered.
Return an explicit error for `stop_reason: "refusal"` in both the
non-streaming path and the streaming path (`message_delta`). Regular
replies, including empty `end_turn` replies, are unchanged.
Assisted-by: Claude:claude-opus-5-5
Signed-off-by: Stefan Walcz <stefan.walcz@walcz.de>
Stefan Walcz
1056c62f4c