Acceptance Criteria:\n- tool descriptors from MCP are forwarded to Ollama chat requests\n- models advertise tool support when metadata or heuristics imply function calling\n- chat responses include provider metadata with final token metrics
Test Notes:\n- cargo test -p owlen-core providers::ollama::tests::prepare_chat_request_serializes_tool_descriptors\n- cargo test -p owlen-core providers::ollama::tests::convert_model_marks_tool_capability\n- cargo test -p owlen-core providers::ollama::tests::convert_response_attaches_provider_metadata