UniT: re-ingest with contact filter (11,340 → 387 kept); fix gel_variant to markered (gel has visible dot pattern). Update docs: remove TVL (was DIGIT not Mini), add to Investigated. Grand total: 852,915 frames.

v9: fix channel order. fota_unlabeled + unit swapped R<->B (were BGR-stored). Refresh sample grids + RGB-vs-BGR comparison + channel_order_diagnosis.json

add UniT (11,340 frames) + TacQuad full (12,195 frames across 181 objects); deprecate tacquad_mini