feat: 更新默认提供者配置，修改基础URL和模型ID

src/config/mod.rs

@@ -927,14 +927,14 @@ impl Config {
             "providers": {
                 "default": {
                     "type": "openai",
-                    "base_url": "https://api.openai.com/v1",
+                    "base_url": "https://api.deepseek.com",
                     "api_key": "<YOUR_API_KEY>",
                     "extra_headers": {}
                 }
             },
             "models": {
                 "default": {
-                    "model_id": "gpt-4o",
+                    "model_id": "deepseek-v4-flash",
                     "temperature": 0.7,
                     "context_window_tokens": 128000
                 }