While laying out a receiver sub-board, the authors found that hw/pack/pack.kicad_dru was never loaded: KiCad 10 silently drops the whole file over a min_resolved_spokes rule, so every earlier clean DRC on the main board was against defaults. Separately, the pcbnew zone fill ignored the RF netclass gap, so the saved fill now comes from kicad-cli, and guard tests were added that prove the rules load.