0537b40dcc
Three-tier test orchestrator validates opcode maps, bit widths, packet layouts, and round-trip correctness across FPGA RTL, Python GUI, and STM32 firmware. Catches 3 real bugs: - status_words[0] 37-bit truncation in both USB interfaces - Python radar_mode readback at wrong bit position (bit 21 vs 24) - RadarSettings.cpp buffer overread (min check 74 vs required 82) 29 tests: 24 pass, 5 xfail (documenting confirmed bugs). 4th CI job added: cross-layer-tests (Python + iverilog + cc).