The sar3d processor is rewritten as a checked port of Multi_antenna_3D_clean_v1.ipynb:
NVRTC kernels, timing from the trace stamps, notebook parameter names and one cubic
SAR_VOXEL_M. It adds front, side, top and 3D views, drops gpr_cpp and the parity tools,
and the GUI speed now applies only while the socket speed is ignored.
Verified on the bench that the modified master bitstream excites in every stage
and the RF switch routes: 16 traces per sweep, 62 dB between the two switch
positions of one master port, 9.9k measurements/s. Adds the built master image,
two run profiles, a verification script and librevna_protocol.md, and drops the
stale prototype driver copy that the firmware tree still carried.