AES-128-CTR (public LongFast key) + minimal protobuf walk. Verified against
packets our scanner captured on-air: decoded a live NodeInfo (longName
'Arch Optiplex', shortName 'ARCH') and POSITION packets. Serves as the
reference for the on-chip C++ port in src/main.cpp.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
