- separate global Host state from tab-local shell and Page state
- replicate control-plane snapshots through a versioned BroadcastChannel
- handshake new tabs without publishing empty startup state
- reject self, stale, and malformed cross-tab messages
- suppress broadcast echoes while applying remote snapshots
- publish API snapshots and connection state atomically
- keep Page state private and update only mounted iframe documents
- test initial synchronization and protocol rejection paths
Maofeng