重构: 连接切换链收敛与代码清理

- 切换连接统一switchConnection入口，删watcher与抑制机制
- 删除活跃服务器后回落本地并加载
- 侧边栏与指示器点击统一上抛，重复点击可刷新
- Wails事件解析归一，查重谓词抽公共
- 删空壳别名文件与过期文档截图

frontend/src/components/UpdatePanel.vue

@@ -120,6 +120,7 @@ import { IconHistory } from '@arco-design/web-vue/es/icon'
 import { useUpdateStore } from '../stores/update'
 import { parseMarkdown, isMarkedReady, preloadMarked } from '../utils/markedExtensions'
 import { sanitizeHtml } from '@/utils/fileUtils'
+import { parseWailsEventData } from '@/utils/wailsEvent'
 import { GetCurrentVersion, GetUpdateConfig, InstallUpdate } from '../wailsjs/v3-bindings/u-desk/app'
 import { On, Off } from '@wailsio/events'
 
@@ -228,12 +229,7 @@ const handleInstall = async () => {
 
 // 监听下载完成事件（本地覆盖：记录下载文件路径）
 const onDownloadComplete = (event) => {
-  let data: any
-  try {
-    data = typeof event === 'string' ? JSON.parse(event) : event
-  } catch {
-    return
-  }
+  const data = parseWailsEventData(event)
 
   if (data.success && data.file_path) {
     downloadedFile.value = data.file_path