Optional per-event payload shapes. Subscribers calling
EventApi.on<T>(name, listener) may supply a type parameter
matching one of these.
Intentionally loose at the type-system level — emitters and
subscribers coordinate on shapes by convention. A stricter
mapping (e.g. discriminated union on event name) can land if
the looseness causes drift.
Full overlay-state snapshot, fired whenever StreamState mutates
(the stream verb is the v1 emitter). The BroadcastFeed
projection listens and re-pushes to broadcast connections. Carries
the whole snapshot so the listener never has to re-read the
singleton.
Optional per-event payload shapes. Subscribers calling
EventApi.on<T>(name, listener)may supply a type parameter matching one of these.Intentionally loose at the type-system level — emitters and subscribers coordinate on shapes by convention. A stricter mapping (e.g. discriminated union on event name) can land if the looseness causes drift.