重构：Wails v3 迁移 + 前端目录规范化 + Sidebar滚动优化

- web/ → frontend/ 目录重命名（Wails v3 标准结构）
- main.go: Middleware 修复 custom.js 404 + DevTools 延迟启动
- Sidebar: 收藏夹内部独立滚动 + 帮助区块固定底部
- useFavorites.ts: longPressTimer const→let 修复 TypeError
- App.vue: Arco Tabs padding-top 覆盖
- build: config.yml / Taskfile.yml 对齐官方模板，devtools build tag
- 新增 v3 bindings、vite.config.js、跨平台构建配置

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

main.go

@@ -2,42 +2,85 @@ package main
 
 import (
 	"embed"
+	"net/http"
+	"time"
 
-	"u-desk/internal/filesystem"
-
-	"github.com/wailsapp/wails/v2"
-	"github.com/wailsapp/wails/v2/pkg/options"
-	"github.com/wailsapp/wails/v2/pkg/options/assetserver"
+	"github.com/wailsapp/wails/v3/pkg/application"
 )
 
-//go:embed all:web/dist
+//go:embed all:frontend/dist
 var assets embed.FS
 
+// 标题栏颜色（0x00BBGGRR）
+var (
+	titleBarLight = uint32(0xF0F0F0) // #F0F0F0 近白
+	titleBarDark  = uint32(0x2D2D2D)  // #2D2D2D 深灰
+)
+
 func main() {
-	// 创建应用实例
 	app := NewApp()
 
-	// 创建应用配置（无边框窗口，自定义标题栏）
-	err := wails.Run(&options.App{
-		Title:     "U-Desk",
-		Width:     1400,
-		Height:    900,
-		MinWidth:  1000,
-		MinHeight: 600,
-		Frameless: true, // 无边框窗口
-		AssetServer: &assetserver.Options{
-			Assets:  assets,
-			Handler: filesystem.NewLocalFileHandler(),
+	wailsApp := application.New(application.Options{
+		Name:        "U-Desk",
+		Description: "桌面文件管理器",
+		Services: []application.Service{
+			application.NewService(app),
 		},
-		BackgroundColour: &options.RGBA{R: 255, G: 255, B: 255, A: 1},
-		OnStartup:        app.Startup,
-		OnShutdown:       app.Shutdown,
-		Bind: []interface{}{
-			app,
+		Assets: application.AssetOptions{
+			Handler: application.AssetFileServerFS(assets),
+			Middleware: func(next http.Handler) http.Handler {
+				return http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
+					if req.URL.Path == "/wails/custom.js" {
+						// custom.js 未使用，返回空响应避免 404 控制台报错
+						rw.Header().Set("Content-Type", "application/javascript")
+						rw.WriteHeader(200)
+						return
+					}
+					next.ServeHTTP(rw, req)
+				})
+			},
+		},
+		Mac: application.MacOptions{
+			ApplicationShouldTerminateAfterLastWindowClosed: true,
 		},
 	})
 
-	if err != nil {
+	window := application.Get().Window.NewWithOptions(application.WebviewWindowOptions{
+		Title:            "U-Desk",
+		Width:            1400,
+		Height:           900,
+		MinWidth:         1000,
+		MinHeight:        600,
+		BackgroundColour: application.NewRGB(255, 255, 255),
+		URL:              "/",
+		Frameless: true,
+			// 保留 Windows 11 原生装饰（圆角 + Aero 阴影）
+		Windows: application.WindowsWindow{
+			Theme: application.SystemDefault,
+			CustomTheme: application.ThemeSettings{
+				LightModeActive: &application.WindowTheme{
+					TitleBarColour: &titleBarLight,
+					BorderColour:   &titleBarLight,
+				},
+				DarkModeActive: &application.WindowTheme{
+					TitleBarColour: &titleBarDark,
+					BorderColour:   &titleBarDark,
+				},
+			},
+		},
+	})
+
+	app.SetMainWindow(window)
+
+	// production+devtools 模式下 OpenInspectorOnStartup 不生效（需 debugMode=true）
+	// 手动延迟调用 OpenDevTools 弹出 Inspector
+	// TODO: 替换为 OnDomReady 回调，当前 alpha.80 可能未稳定支持
+	go func() {
+		time.Sleep(2 * time.Second)
+		_ = window.OpenDevTools()
+	}()
+
+	if err := wailsApp.Run(); err != nil {
 		println("Error:", err.Error())
 	}
 }