H743 FC is now wired to Serial2 (RX=GPIO18, TX=GPIO17, 57600 baud).
ESP32 becomes a raw byte relay: UART→UDP and UDP→UART on port 14550.
Removed fake heartbeat generator — real heartbeat comes from H743.
Added byte counters with periodic stats log every 10s.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>