Method startHeartbeat

packages/server/src/utils/SSEStreamer.ts:372–379

(intervalMs: number = 30_000)

    }

    startHeartbeat(intervalMs: number = 30_000) {
        this.heartbeatInterval = setInterval(() => {
            for (const chatId of this.clients.keys()) {
                // SSE comment line — ignored by clients but keeps the connection alive through ALB/proxies
                this.safeWrite(chatId, ':heartbeat\n\n')
            }
        }, intervalMs)
    }

    stopHeartbeat() {
        if (this.heartbeatInterval) {