The agent's last_seen IP was showing the Docker container IP (10.244.x.x)
because conn.remote_ip returns the proxy/load balancer IP.
Changes:
- Added get_client_ip/1 helper that checks X-Forwarded-For first
- Falls back to X-Real-IP if X-Forwarded-For not present
- Falls back to conn.remote_ip as last resort
- Applied to both AgentAuth plug and AgentController heartbeat endpoint
Now correctly shows the actual external IP of the remote agent.