新增: 自动升级体系 + WorkerW重建检测 + 知识卡片优化

自动升级:
- 版本变量注入 (-ldflags -X main.version)
- 远程 version.json 检查 + 弹窗提示(非强制右下角/强制居中)
- updater.exe 嵌入主程序, 运行时释放到临时目录
- 下载+SHA256校验+备份+替换+回滚 全流程
- 托盘菜单"检查更新"

稳定性:
- WorkerW 重建自动检测(每10s)并重新嵌入
- 左键托盘点击防抖
- 设置窗口已打开时正确前置

优化:
- 知识卡片prompt改为面向开发者的硬核内容
- 配置目录统一到 ~/.u-desktop/
- 设置窗口WebView2数据目录改为configDir下

systray.go

@@ -18,10 +18,35 @@ func onSystrayReady() {
 	systray.SetIcon(trayIcon)
 	systray.SetTooltip("动态壁纸引擎")
 
+	// 左键点击托盘图标 → 打开设置（防抖: 连续点击只响应一次）
+	go func() {
+		for range systray.TrayClickCh {
+			openSettingsWindow()
+			// 消费后续积压的点击
+			for {
+				select {
+				case <-systray.TrayClickCh:
+				default:
+					goto done
+				}
+			}
+		done:
+		}
+	}()
+
 	mSettings := systray.AddMenuItem("桌面设置", "打开设置窗口")
+	mCheckUpdate := systray.AddMenuItem("检查更新", "检查是否有新版本")
 	mRestart := systray.AddMenuItem("重启", "重启程序")
 	mQuit := systray.AddMenuItem("退出", "退出程序")
 
+	// 检查更新
+	go func() {
+		for {
+			<-mCheckUpdate.ClickedCh
+			manualCheckUpdate()
+		}
+	}()
+
 	// 设置窗口
 	go func() {
 		for {
@@ -53,6 +78,7 @@ func onSystrayReady() {
 	go bingWallpaperLoop()
 	go knowledgeLoop()
 	go startPhotoLoop()
+	go runAutoUpdateCheck()
 }
 
 func startWebView() {
@@ -89,10 +115,10 @@ func startWebView() {
 	wvHwnd = uintptr(wv.Window())
 	procShowWindow.Call(wvHwnd, 0) // SW_HIDE
 	procSetWindowLongPtrW.Call(wvHwnd, gwlStyle, wsPopup|wsVisible|wsChild)
+	procSetWindowLongPtrW.Call(wvHwnd, gwlExStyle, wsExTransparent|wsExLayered)
 
 	// 立即嵌入 WorkerW
-	procSetParent.Call(wvHwnd, workerw)
-	procMoveWindow.Call(wvHwnd, uintptr(^uint(0)), uintptr(^uint(0)), uintptr(screenW+2), uintptr(screenH+2), 1)
+	embedWorkerW(workerw, screenW, screenH)
 	log.Printf("已嵌入 WorkerW: HWND=0x%x, %dx%d", wvHwnd, screenW, screenH)
 
 	wv.Bind("setZodiacFromGo", func(zodiac string) error {
@@ -158,11 +184,35 @@ func startWebView() {
 	}
 }
 
+func embedWorkerW(workerw uintptr, screenW, screenH int32) {
+	procSetParent.Call(wvHwnd, workerw)
+	procMoveWindow.Call(wvHwnd, uintptr(^uint(0)), uintptr(^uint(0)), uintptr(screenW+2), uintptr(screenH+2), 1)
+}
+
 func fullscreenMonitor() {
 	type rect struct{ Left, Top, Right, Bottom int32 }
 	var lastState string
+	var lastParent uintptr
+	var parentTick int
 	for {
 		if atomic.LoadInt32(&paused) == 0 && wv != nil {
+			// 每 5 轮(10s)检测一次父窗口，极轻量系统调用
+			parentTick++
+			if parentTick >= 5 {
+				parentTick = 0
+				parent, _, _ := procGetParent.Call(wvHwnd)
+				if parent != lastParent {
+					lastParent = parent
+					ww := findWorkerW()
+					if ww != 0 && ww != parent {
+						screenW, screenH := getScreenSize()
+						embedWorkerW(ww, screenW, screenH)
+						procShowWindow.Call(wvHwnd, 5)
+						log.Printf("WorkerW 变更，已重新嵌入: 0x%x → 0x%x", parent, ww)
+					}
+				}
+			}
+
 			fg, _, _ := procGetForegroundWindow.Call()
 			if fg != 0 {
 				var r rect