steveandClaude Opus 5
02cd561eaf
Adds the `qwen` built-in provider and the `qwen://` DSN scheme, keyed by QWEN_API_KEY and defaulting to Model Studio's international host. Like kimi (ADR-0026) it is `provider/openai` pointed elsewhere — no new client. Model Studio serves the same models over two protocols, so the real decision was which wire format to speak. ADR-0027 records why it is the OpenAI one: down the anthropic client `ReasoningEffort` is ignored by design, structured output rides the first-party `output_config.format` mechanism the shim does not implement, and cached-token accounting reads Anthropic-only usage fields. Each of those fails silently rather than loudly, which is what makes the choice worth writing down. The shim stays reachable ad hoc via an `anthropic://` DSN. The kimi and qwen DSN factories were byte-identical, so they now share one `openaiCompatScheme` helper: the "credential comes from the DSN token, and the missing-key hint names LLM_<NAME>" rules hold by construction instead of by copy. Tests are hermetic and break-checked (all six fail on a deliberate mutation), including the reverse credential leak — a visible QWEN_API_KEY must not authenticate the openai built-in — and reasoning_effort asserted on the wire body, which is the ADR's load-bearing claim. Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>