Sky130A Cell Layout Verification Dataset and PEX Benchmark

This release contains a provenance census of Sky130A cell layout candidates, verified cell bundles, and a post-layout parasitic extraction (PEX) benchmark. The bundles include layout files, independent reference schematics, and recorded design rule checking (DRC), layout versus schematic (LVS), and PEX evidence. The benchmark provides resistance and capacitance labels, a frozen library-family transfer split, baseline predictions, and scores. The recorded tool results do not constitute design sign-off. Each verified bundle includes its source license; source and PDK license notices are provided in THIRD_PARTY_NOTICES.md.