The Codex/OpenAI Responses API does not support the stream_options
parameter. When clients (e.g. Amp CLI) include stream_options in their
requests, CLIProxyAPI forwards it as-is, causing a 400 error:
{"detail":"Unsupported parameter: stream_options"}
Strip stream_options alongside the other unsupported parameters
(previous_response_id, prompt_cache_retention, safety_identifier)
in Execute, ExecuteStream, and CountTokens.