Shadcn Guideline: Sidebar — Wrap in SidebarProvider. Description: Use SidebarProvider for sidebar state management. Do: SidebarProvider at layout level. Don't: Sidebar without provider. Good Example: <SidebarProvider><Sidebar></SidebarProvider>. Bad Example: <Sidebar> without provider. Severity: High. Docs: https://ui.shadcn.com/docs/components/sidebar.