WebSocket Live Stream (issue #3)

[MohamedEBR]

Summary

Implement the WebSocket broadcast layer in Express to deliver real-time telemetry updates to all connected clients.

Details

This module should allow browsers to subscribe to a specific session and receive live updates.
The system must isolate sessions, handle client backpressure, and ensure minimal latency from Jetson to dashboard.

Tasks

• Add /ws/live endpoint with WebSocket support in Express
• Implement session-based broadcasting for connected clients
• Relay telemetry data from the ingest service to all active WebSocket clients
• Add per-client message buffer and discard oldest messages when lagging
• Enable compression and heartbeat pings for stable connections
• Test end-to-end latency and synchronization across multiple browsers

Deliverable

A functional WebSocket system integrated with the ingest service, streaming live telemetry to the frontend dashboard.