Shadcn Guideline: Sidebar — Use SidebarTrigger. Description: Include SidebarTrigger for mobile toggle. Do: SidebarTrigger for responsive toggle. Don't: Custom toggle button. Good Example: <SidebarTrigger/>. Bad Example: <Button onClick={() => toggleSidebar()}>. Severity: Medium. Docs: https://ui.shadcn.com/docs/components/sidebar.