Interface ShadowChangedPayload

ShadowChangedEvent — declared for use by subscribable-field descriptors that want re-resolution on shadow attach / detach / mutate.

Ships declared but unfired. The firing site lights up with the shadow lifecycle hooks in a later subsystem build. Subscribable- field descriptors that participate in shadowed projection (Name / Visible / Detail) declare this event in their changes array so the meta-bus index is wired end-to-end; until the firing site exists, the listener is silent.

Concrete event classes don't extend a common base — they satisfy the BusEvent<P> structural contract (in api/event.ts) by declaring kind: string + payload: P directly.