Cross-Process Event Bridge

Mirror real-time events (message/room/role/user-to-room/call state) to Azure Web PubSub for cross-process fan-out, with a receiveWebPubSubEvent dispatcher re-emitting them into the local EventEmitter and idempotency keys to prevent double-apply.

Why deferred

• The app runs a single Node process today; the in-process EventEmitter is correct and sufficient.
• The plumbing (publish boundary + WebPubSub mirror + dispatcher + per-event idempotency/dedup) is real distributed-systems work that is easy to get subtly wrong.
• It is speculative: it builds fan-out for a scaling event that may never happen.

Revisit when: the app actually runs more than one replica (or needs cross-process delivery for another concrete reason). Going multi-replica is a deliberate decision — build this at that moment, not before.