Connect to Tracker-Test-Setup, then upload a compiled .bin (no USB needed).
Arduino IDE: Sketch → Export compiled Binary, then choose the .ino.bin for XIAO_ESP32C6.
Required: Tools → Partition Scheme → No OTA (2MB APP/2MB SPIFFS) so the IDE size check allows ~1.63MB firmware. Sketch partitions.csv still lays out dual OTA + 384KB LittleFS.
Keep the phone/laptop on collar Wi-Fi until it reboots. Free heap: 198060 | Sketch MD5 will change after flash.
Device reboots automatically. Reconnect to Tracker-Test-Setup and open http://192.168.4.1/