Client component met states loading/unsupported/ios-needs-install/
denied/subscribed/unsubscribed. useEffect detecteert initial status,
permission-prompt alleen via user-click. iOS-banner NL, denied-uitleg,
subscribe/unsubscribe knoppen met sonner-toasts.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
