feat: event bus with Redpanda + AI insight consumer

- EventBusService: Kafka/Redpanda pub/sub with kafkajs, graceful fallback when broker unavailable
- Topics: call.completed, call.missed, agent.state
- AiInsightConsumer: on call.completed, fetches lead activity → OpenAI generates summary + suggested action → updates Lead entity on platform
- Disposition endpoint emits call.completed event after Ozonetel dispose
- EventsModule registered as @Global for cross-module injection
- Redpanda container added to VPS docker-compose
- Docker image rebuilt for linux/amd64 with kafkajs dependency

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

package-lock.json

@@ -24,6 +24,7 @@
         "ai": "^6.0.116",
         "axios": "^1.13.6",
         "ioredis": "^5.10.1",
+        "kafkajs": "^2.2.4",
         "reflect-metadata": "^0.2.2",
         "rxjs": "^7.8.1",
         "socket.io": "^4.8.3",
@@ -10569,6 +10570,15 @@
         "safe-buffer": "^5.0.1"
       }
     },
+    "node_modules/kafkajs": {
+      "version": "2.2.4",
+      "resolved": "http://localhost:4873/kafkajs/-/kafkajs-2.2.4.tgz",
+      "integrity": "sha512-j/YeapB1vfPT2iOIUn/vxdyKEuhuY2PxMBvf5JWux6iSaukAccrMtXEY/Lb7OvavDhOWME589bpLrEdnVHjfjA==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=14.0.0"
+      }
+    },
     "node_modules/keyv": {
       "version": "4.5.4",
       "resolved": "http://localhost:4873/keyv/-/keyv-4.5.4.tgz",