Streaming via goroutine+channel bridge (range-based iter.Seq2 → pull
iterator). Tool use with FunctionCall/FunctionResponse, tool name
sanitization, tool name map for FunctionResponse correlation.
Stop reason override (Google uses STOP for function calls).
Hardcoded model list (gemini-2.5-pro/flash, gemini-2.0-flash).
Wired into CLI with GOOGLE_API_KEY + GEMINI_API_KEY env support.
Live verified: text streaming + tool calling with gemini-2.5-flash.
Four providers now live: Mistral, Anthropic, OpenAI, Google.