ESPresense: room-level presence detection with ESP32 nodes

ESPresense turns ESP32 boards into Bluetooth presence nodes. Each node listens for phones, watches and beacons, estimates distance and publishes it over MQTT, with Home Assistant MQTT discovery. It identifies devices by fingerprint rather than MAC address, and supports IRK-based enrollment so Apple devices with private random addresses can still be located. Distances are smoothed with a median pre-filter and a 1Euro filter to cut jitter. There are two ways to use it: one node per room with Home Assistant's mqtt_room for simple room automations, or dense coverage (the docs suggest 5 to 8 nodes per floor) with ESPresense-companion for X,Y positions on a floor plan. You need the nodes, something to track and an MQTT server.