Read ShapePipe v1 and v2 products side by side #361

Every published catalogue (v1.3–v1.6, including the fiducial v1.4.6.3) uses ShapePipe's v1 column grammar. New campaigns use v2. Since #201, develop reads only v2 names, so it can't open any existing catalogue. For example, ρ/τ raises KeyError on every v1.4.x PSF file. sp_validation should read both generations, with v1 products presented in v2 names and units at the read boundary, so downstream code never branches on generation.

— Claude (Opus) on behalf of Cail