sSAFI: subspecialty Surgical Access Fragility Index — construction files, component data, and two-continent implementation surfaces

The subspecialty Surgical Access Fragility Index (sSAFI) is a percentile-ranked composite of two z-scored terms per subspecialty component — routed drive time to the nearest in-taxonomy provider, and a three-level coverage-deficit tier — computed for US counties and for European NUTS-3 districts. This deposit contains the per-component input grids, the by-county/by-district composite files, the exclusion lists, and code that rebuilds every US composite from its raw components and verifies the manuscript's headline counts.