fix: wire activity.logged event to WebSocket broadcast

Add @OnEvent('activity.logged') listener in EventsGateway to bridge
EventEmitter2 → WebSocket activity:new broadcast. Restores real-time
activity push without reintroducing circular dependency.

backend/src/events/events.gateway.ts

@@ -10,6 +10,7 @@ import { Server, Socket } from 'socket.io';
 import { Logger } from '@nestjs/common';
 import { JwtService } from '@nestjs/jwt';
 import { ConfigService } from '@nestjs/config';
+import { OnEvent } from '@nestjs/event-emitter';
 
 interface SocketUserPayload {
   username?: string;
@@ -101,6 +102,12 @@ export class EventsGateway
     this.server.emit('activity:new', { item, ts: Date.now() });
   }
 
+  /** EventEmitter2에서 activity.logged 수신 → WebSocket 브로드캐스트 */
+  @OnEvent('activity.logged')
+  handleActivityLogged(record: unknown) {
+    this.broadcastActivity(record);
+  }
+
   /** 연결된 클라이언트 수 */
   getClientCount(): number {
     return this.server?.sockets?.sockets?.size ?? 0;