大模型 Provider 配置

按 priority 升序 fallback。常用配置:
· 火山豆包 base_url = https://ark.cn-beijing.volces.com/api/coding/v3,model = Doubao-Seed-2.0-pro,extra_params = {"thinking": false}
· DeepSeek base_url = https://api.deepseek.com/v1,model = deepseek-chat
优先级名称厂商模型API Key状态操作