PlatformIO project for ESP32-S3 + SX1262 (Heltec WiFi LoRa 32 V3). Transmits periodic LoRa packets matching gr-lora_sdr receiver params: SF7, BW125kHz, CR4/5, 915MHz, sync word 0x12, CRC enabled. Verified end-to-end: beacon TX → RTL-SDR → Docker gr-lora_sdr → decoded "GR-MCP #N" payloads with valid CRC.