refactor: improve error handling and code formatting

- Enhanced error messages in Rust backend to include file paths
- Improved provider switching error handling with detailed messages
- Added MCP button placeholder in UI (functionality TODO)
- Applied code formatting across frontend components
- Extended error notification duration to 6s for better readability

src/components/JsonEditor.tsx

@@ -53,7 +53,8 @@ const JsonEditor: React.FC<JsonEditorProps> = ({
           }
         } catch (e) {
           // 简单处理JSON解析错误
-          const message = e instanceof SyntaxError ? e.message : t("jsonEditor.invalidJson");
+          const message =
+            e instanceof SyntaxError ? e.message : t("jsonEditor.invalidJson");
           diagnostics.push({
             from: 0,
             to: doc.length,