chore: bootstrap Go project with cobra skeleton

cmd/archduino/main.go

@@ -0,0 +1,45 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+var version = "dev"
+
+func main() {
+	root := &cobra.Command{
+		Use:           "archduino",
+		Short:         "Archduino installer and toolbox",
+		SilenceUsage:  true,
+		SilenceErrors: true,
+		Version:       version,
+	}
+
+	root.AddCommand(newInstallCmd())
+
+	if err := root.Execute(); err != nil {
+		fmt.Fprintln(os.Stderr, "error:", err)
+		os.Exit(1)
+	}
+}
+
+func newInstallCmd() *cobra.Command {
+	var noTUI bool
+	var dryRun bool
+	cmd := &cobra.Command{
+		Use:   "install",
+		Short: "Install or reconcile the Archduino toolset",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			// Foundation scaffold: real wiring lands in Task 11.
+			fmt.Println("archduino install (stub)")
+			fmt.Printf("  --no-tui=%v --dry-run=%v\n", noTUI, dryRun)
+			return nil
+		},
+	}
+	cmd.Flags().BoolVar(&noTUI, "no-tui", false, "plain-text output, no interactive UI")
+	cmd.Flags().BoolVar(&dryRun, "dry-run", false, "show planned actions without applying")
+	return cmd
+}