新增: - /engine.openai think [on|off|low|medium|high] 命令 - deep_think 配置项 (config.json) - reasoning_effort 参数 (low/medium/high) 支持模型: - DeepSeek: enable_thinking + reasoning_content - OpenAI o-series: reasoning.effort - 通用: reasoning_effort 参数 深度思考开启后: - 自动注入思考参数到请求体 - 返回的思维链(reasoning_content)显示在终端 - info 命令显示当前思考状态