SynchroMesh: Autonomous Swarm Logistics

Design a real-time coordination system for a fleet of 10 million autonomous delivery drones operating in high-density urban environments. The system must process GPS and telemetry updates every second, provide dynamic rerouting based on hyper-local weather and air-traffic congestion, and ensure zero collisions with a latency of under 100ms for command overrides. It must also handle 'dark zones' where connectivity is lost and re-sync state gracefully upon reconnection.