The server parsed rssi from buf[14] and noise_floor from buf[15], but
the firmware (csi_collector.c) packs them at buf[16] and buf[17]:
Firmware: n_subcarriers=u16(6-7) freq=u32(8-11) seq=u32(12-15) rssi=i8(16)
Server: n_subcarriers=u8(6) freq=u16(8-9) seq=u32(10-13) rssi=i8(14) ← WRONG
This caused RSSI to read the high byte of the sequence counter instead
of the actual signed RSSI value, producing positive values (e.g., +9)
instead of the correct negative values (e.g., -46 dBm).
Added inline documentation of the frame layout matching csi_collector.c.
Closes#332
Co-Authored-By: claude-flow <ruv@ruv.net>
74a6a25905