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>

src/events/event-bus.service.ts

@@ -0,0 +1,114 @@
+import { Injectable, Logger, OnModuleInit, OnModuleDestroy } from '@nestjs/common';
+import { Kafka, Producer, Consumer, EachMessagePayload } from 'kafkajs';
+import type { EventPayload } from './event-types';
+
+type EventHandler = (payload: any) => Promise<void>;
+
+@Injectable()
+export class EventBusService implements OnModuleInit, OnModuleDestroy {
+    private readonly logger = new Logger(EventBusService.name);
+    private kafka: Kafka;
+    private producer: Producer;
+    private consumer: Consumer;
+    private handlers = new Map<string, EventHandler[]>();
+    private connected = false;
+
+    constructor() {
+        const brokers = (process.env.KAFKA_BROKERS ?? 'localhost:9092').split(',');
+        this.kafka = new Kafka({
+            clientId: 'helix-engage-sidecar',
+            brokers,
+            retry: { retries: 5, initialRetryTime: 1000 },
+            logLevel: 1, // ERROR only
+        });
+        this.producer = this.kafka.producer();
+        this.consumer = this.kafka.consumer({ groupId: 'helix-engage-workers' });
+    }
+
+    async onModuleInit() {
+        try {
+            await this.producer.connect();
+            await this.consumer.connect();
+            this.connected = true;
+            this.logger.log('Event bus connected (Kafka/Redpanda)');
+
+            // Subscribe to all topics we have handlers for
+            // Handlers are registered by consumer modules during their onModuleInit
+            // We start consuming after a short delay to let all handlers register
+            setTimeout(() => this.startConsuming(), 2000);
+        } catch (err: any) {
+            this.logger.warn(`Event bus not available (${err.message}) — running without events`);
+            this.connected = false;
+        }
+    }
+
+    async onModuleDestroy() {
+        if (this.connected) {
+            await this.consumer.disconnect().catch(() => {});
+            await this.producer.disconnect().catch(() => {});
+        }
+    }
+
+    async emit(topic: string, payload: EventPayload): Promise<void> {
+        if (!this.connected) {
+            this.logger.debug(`[EVENT] Skipped (not connected): ${topic}`);
+            return;
+        }
+
+        try {
+            await this.producer.send({
+                topic,
+                messages: [{ value: JSON.stringify(payload), timestamp: Date.now().toString() }],
+            });
+            this.logger.log(`[EVENT] Emitted: ${topic}`);
+        } catch (err: any) {
+            this.logger.error(`[EVENT] Failed to emit ${topic}: ${err.message}`);
+        }
+    }
+
+    on(topic: string, handler: EventHandler): void {
+        const existing = this.handlers.get(topic) ?? [];
+        existing.push(handler);
+        this.handlers.set(topic, existing);
+        this.logger.log(`[EVENT] Handler registered for: ${topic}`);
+    }
+
+    private async startConsuming(): Promise<void> {
+        if (!this.connected) return;
+
+        const topics = Array.from(this.handlers.keys());
+        if (topics.length === 0) {
+            this.logger.log('[EVENT] No handlers registered — skipping consumer');
+            return;
+        }
+
+        try {
+            for (const topic of topics) {
+                await this.consumer.subscribe({ topic, fromBeginning: false });
+            }
+
+            await this.consumer.run({
+                eachMessage: async (payload: EachMessagePayload) => {
+                    const { topic, message } = payload;
+                    const handlers = this.handlers.get(topic) ?? [];
+                    if (handlers.length === 0 || !message.value) return;
+
+                    try {
+                        const data = JSON.parse(message.value.toString());
+                        for (const handler of handlers) {
+                            await handler(data).catch(err =>
+                                this.logger.error(`[EVENT] Handler error on ${topic}: ${err.message}`),
+                            );
+                        }
+                    } catch (err: any) {
+                        this.logger.error(`[EVENT] Parse error on ${topic}: ${err.message}`);
+                    }
+                },
+            });
+
+            this.logger.log(`[EVENT] Consuming: ${topics.join(', ')}`);
+        } catch (err: any) {
+            this.logger.error(`[EVENT] Consumer failed: ${err.message}`);
+        }
+    }
+}