v9 splits useFullscreen into useFullscreenElement (ref-based) and
useFullscreenDocument. NavigationMenu never attached the ref, and v8's
useFullscreen fell back to document.documentElement in that case, so
useFullscreenDocument is a behaviourally identical swap.
Every other hook in use is unaffected. The one other breaking change —
useLocalStorage/useSessionStorage now return `T | undefined` when no
defaultValue is given — does not apply: all nine call sites pass one.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NWs1vf42msmoJ21ABvQMpm
Carlos Valente
3f4a919483