New protocol command (tag 8): GetMac returns the board's 6-byte hardware
address. Useful when multiple dongles are connected to one host.
Response (tag 6): MacAddress containing 6 raw bytes.
Updated: PROTOCOL.md, CHANGELOG, donglora.py decoder, all_commands.py.
Config response (GetConfig) now returns decoded RadioConfig fields instead
of raw hex. New all_commands.py exercises all 8 protocol commands in
sequence — Ping, SetConfig, GetConfig, StartRx, StopRx, Transmit,
DisplayOff, DisplayOn.