⚡️(frontend) add component to render children only for Admin or User

Introduce a component that renders its children only if the logged-in
user is considered Admin or User. This helps avoid mounting the hooks
and logic of components that previously early-returned when the user
was not admin or owner, but were still re-rendering whenever their
internal logic updated.

src/frontend/src/features/rooms/components/AdminOrOwnerOnly.tsx

@@ -0,0 +1,11 @@
+import { useIsAdminOrOwner } from '@/features/rooms/livekit/hooks/useIsAdminOrOwner'
+
+export const AdminOrOwnerOnly = ({
+  children,
+}: {
+  children: React.ReactNode
+}) => {
+  const isAdminOrOwner = useIsAdminOrOwner()
+  if (!isAdminOrOwner) return null
+  return children
+}