Function usePresenterSync

usePresenterSync(options: PresenterSyncOptions): PresenterSyncReturn
Synchronises presenter state across room participants via the semantic relay (low-latency QUIC datagrams).

The presenter broadcasts sidebar / tab / file-open state changes; followers receive and apply them. The relay envelope already carries a senderId and messageId, so this hook delegates self-message filtering and messageId dedup to useRelaySubProtocol. A separate timestamp check inside the payload still drops messages that arrived out-of-order from a slow peer.
Parameters
- options: PresenterSyncOptions
Returns PresenterSyncReturn
Example: Presenter (owner)
```
const { broadcastState } = usePresenterSync({
  localUserId: user.id,
  isPresenter: true,
  enabled: syncEnabled,
});

// In PrebuiltRoom callbacks:
onSidebarOpenChanged={(open) => broadcastState({ sidebarOpen: open })}
onActiveTabChanged={(tab) => broadcastState({ activeTab: tab })}
```
Example: Follower (participant)
```
const { presenterState, isFollowing } = usePresenterSync({
  localUserId: user.id,
  isPresenter: false,
  enabled: true,
});

// Pass controlled props to PrebuiltRoom when following:
controlledSidebarOpen={isFollowing ? presenterState?.sidebarOpen : undefined}
controlledActiveTab={isFollowing ? presenterState?.activeTab : undefined}
```
- Defined in hooks/usePresenterSync.ts:67