chore(wails): scaffold v3 project boilerplate

Wails v3 replaces the NPM-only dev entry point. This adds the Go module,
Taskfile, build metadata, and a minimal window shell without touching
frontend logic.

Co-authored-by: Cursor <cursoragent@cursor.com>

main.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"embed"
+	"log"
+
+	"github.com/wailsapp/wails/v3/pkg/application"
+)
+
+//go:embed all:frontend/dist
+var assets embed.FS
+
+func main() {
+	app := application.New(application.Options{
+		Name:        "sfxkeeb",
+		Description: "Annotate keyboard key presses on a video timeline",
+		Assets: application.AssetOptions{
+			Handler: application.AssetFileServerFS(assets),
+		},
+		Mac: application.MacOptions{
+			ApplicationShouldTerminateAfterLastWindowClosed: true,
+		},
+	})
+
+	app.Window.NewWithOptions(application.WebviewWindowOptions{
+		Title:  "sfxkeeb",
+		Width:  1280,
+		Height: 900,
+		MinWidth:  960,
+		MinHeight: 600,
+		Mac: application.MacWindow{
+			InvisibleTitleBarHeight: 50,
+			Backdrop:                application.MacBackdropTranslucent,
+			TitleBar:                application.MacTitleBarHiddenInset,
+		},
+		BackgroundColour: application.NewRGB(27, 38, 54),
+		URL:              "/",
+	})
+
+	if err := app.Run(); err != nil {
+		log.Fatal(err)
+	}
+}