feat(companion): add event surface snapshot helper

src/companion/runtimeClient.ts

@@ -53,6 +53,12 @@ export interface PendingWorkSnapshot {
   hasPendingWork: boolean;
 }
 
+export interface EventSurfaceSnapshot {
+  knownEventNames: CompanionEventName[];
+  eventSubscriptionCount: number;
+  pendingEventWaitCount: number;
+}
+
 export type CompanionEventHandler = (event: string, data: unknown) => void;
 export type CompanionTypedEventHandler<TData = unknown> = (data: TData) => void;
 export type CompanionEventPredicate<TData = unknown> = (data: TData) => boolean;
@@ -338,6 +344,14 @@ export class CompanionRuntimeClient {
     };
   }
 
+  getEventSurfaceSnapshot(): EventSurfaceSnapshot {
+    return {
+      knownEventNames: this.listKnownEventNames(),
+      eventSubscriptionCount: this.eventSubscriptionCount,
+      pendingEventWaitCount: this.pendingEventWaitCount,
+    };
+  }
+
   async connect(): Promise<void> {
     if (this.connected) {
       return;