The file imports useEffect/useRef from React, which Next.js RSC builds
flag as client-only. Other core systems (e.g. elevator-runtime-system)
use useFrame from @react-three/fiber and slip through, but this one
needs the directive explicitly.
Fixes Turbopack build failure in private-editor community app:
"You're importing a module that depends on useEffect into a React
Server Component module."
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
