Add Gio desktop GUI shell

cmd/cli/main.go

@@ -0,0 +1,21 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"vpn-client/internal/cli"
+	"vpn-client/internal/config"
+)
+
+func main() {
+	if err := config.Init(); err != nil {
+		fmt.Fprintf(os.Stderr, "config init error: %v\n", err)
+		os.Exit(1)
+	}
+
+	if err := cli.Run(); err != nil {
+		fmt.Fprintf(os.Stderr, "cli error: %v\n", err)
+		os.Exit(1)
+	}
+}