Real-time MQTT ingestion from plant machines

[Goodnight77]

Goal: connect TORQ to real machine fault events over MQTT in real time (real plant integration).

Already done

• events/listener.py subscribes to a broker/topic (config: MQTT_BROKER_URL / MQTT_PORT / MQTT_TOPIC).
• events/simulator.py publishes fault events (QoS 1) - the demo trigger.
• Malformed-message handling (bad/no-fault_code payloads are ignored).
• Listener runs the full pipeline on each fault (diagnose -> work order).

Still to do (the real gap)

• Real PLC / SCADA / DCS -> MQTT gateway: an edge script reading OPC-UA / Modbus and republishing to our topic, or documented instructions for a plant SCADA to publish. (Needs real plant hardware / broker.)
• Explicit fault schema: machine id, fault_code, timestamp, severity (listener currently parses fault_code / machine / context only).
• Robust reconnect handling and QoS on the subscribe side.
• Live fault feed on the dashboard (overlaps Frontend polish and deploy #11).

Note: real-plant, hardware-dependent integration - tagged future-enhancements (post-hackathon).