Stop advertising and mapping the unsupported gpt-5.1-minimal variant in the model registry and Codex executor, and align bare gpt-5.1 requests to use medium reasoning effort like Codex CLI while preserving minimal for gpt-5.
The OpenAI Codex Responses API (chatgpt.com/backend-api/codex/responses)
rejects requests containing max_output_tokens and max_completion_tokens fields,
causing Factory CLI to fail with "Unsupported parameter" errors.
This fix strips these incompatible fields during request translation, allowing
Factory CLI to work properly with CLIProxyAPI when using ChatGPT Plus/Pro OAuth.
Fixes compatibility issue where Factory sends token limit parameters that aren't
supported by the Codex Responses endpoint.