optimize config display && unused old config

frontend/js/app.js

@@ -81,8 +81,11 @@ async function handleEditConfig(originalFilename) {
         DOMElements.formTitle.textContent = '编辑配置';
         fillForm(config, originalFilename);
         showRenderedConfig(rendered, originalFilename);
+        
+        // 关键修正: 在填充表单后, 根据数据更新服务模式的fieldset可见性
         const mode = config.upstream_config?.enable_upstream ? 'reverse_proxy' : (config.file_server_config?.enable_file_server ? 'file_server' : 'none');
         updateServiceModeView(mode);
+        
         state.initialFormState = getFormStateAsString();
     } catch(error) { notification.toast(`加载配置详情失败: ${error.message}`, 'error'); }
 }