Shadcn Guideline: Dialog — Handle dialog state properly. Description: Use open and onOpenChange for controlled dialogs. Do: Controlled state with useState. Don't: Uncontrolled with default open only. Good Example: <Dialog open={open} onOpenChange={setOpen}>. Bad Example: <Dialog defaultOpen={true}>. Severity: Medium. Docs: https://ui.shadcn.com/docs/components/dialog.