fix: emit() publishes to exchange instead of sendToQueue

NestJS v10 RMQ client uses sendToQueue which sends to a specific
queue (core_queue), bypassing the exchange. Messages were never
delivered to other plugins' queues bound to the exchange.

Changed emit() to use amqplib to publish directly to system_events
exchange with {pattern, data} format that NestJS RMQ server expects.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@erp/plugin-sdk",
-  "version": "1.11.2",
+  "version": "1.11.3",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
   "bin": {

src/backend/services/core.service.ts

@@ -331,9 +331,19 @@ export class CoreService {
       source: this.serviceName,
       timestamp: Date.now(),
     };
-    this.client.emit(pattern, event).subscribe({
-      error: (err) => this.logger.error(`Failed to emit event ${pattern}:`, err),
-    });
+    try {
+      const conn = await amqp.connect(this.getRMQUrl());
+      const ch = await conn.createChannel();
+      await ch.assertExchange('system_events', 'topic', { durable: true });
+      ch.publish('system_events', pattern, Buffer.from(JSON.stringify({
+        pattern,
+        data: event,
+      })));
+      await ch.close();
+      await conn.close();
+    } catch (err: any) {
+      this.logger.error(`Failed to emit event ${pattern}: ${err.message}`);
+    }
   }
 
   async auditLog(action: string, resource: string, details?: any): Promise<void> {