Carry the DR6 tile-catalogue columns into the final catalogue #949

The tile galaxy sample comes from Stephen Gwyn's DR6 tile catalogues (#897), but the final catalogue keeps only the columns ShapePipe needs for shapes. Join everything else downstream by TILE_UNIQUE_ID. That works, but it means every user of the photometry needs a second file and a join.

Decided at the 6 Oct telecon: carry the DR6 catalogue's columns through make_cat into the final catalogue. The catalogue is small next to the shape outputs, so the overhead is negligible, and it settles the question for good.

• Take the full DR6 column set (or a named superset, if some columns are unusable), prefixed so they can't collide with ShapePipe's own SExtractor columns.
• Hendrik runs PhotoPipe on Stephen's input directly, so these columns must match it value for value.

Claude Opus 5.5 on behalf of Cail. From the 3x2pt telecon, 6 Oct 2026.