Print nixos rules on exit

Signed-off-by: Hadi <hadi@example.com>

main.go

@@ -23,8 +23,19 @@ func main() {
 	}
 
 	p := tea.NewProgram(ui.New())
-	if _, err := p.Run(); err != nil {
+	m, err := p.Run()
+	if err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		os.Exit(1)
 	}
+	if fm, ok := m.(ui.Model); ok {
+		if rules := fm.PendingRules(); len(rules) > 0 {
+			fmt.Println("# Add to your NixOS configuration:")
+			fmt.Println("services.usbguard.rules = lib.mkAfter ''")
+			for _, rule := range rules {
+				fmt.Println(" ", rule)
+			}
+			fmt.Println("'';")
+		}
+	}
 }