Implement firmware OTA update logic on an ESP32 using ESP-IDF's native OTA API with dual ota_0/ota_1 partitions

Steps

1. Partition the flash with ota_0 and ota_1 app partitions plus an otadata partition (2 flash sectors, 0x2000 bytes) to track which slot is active
2. Call esp_ota_begin() to open a handle to the inactive partition before writing new firmware
3. Stream the downloaded firmware image into esp_ota_write() (or esp_ota_write_with_offset() for out-of-order chunks) as it arrives
4. Call esp_ota_end() to finalize and validate the written image
5. Call esp_ota_set_boot_partition() to mark the newly written partition as the one to boot from on next reset, then reboot