Each page rendered as one 150-DPI PNG. Page images are stored ONCE per distinct document
under images//pNNNN.png and referenced by each cell question.json (image_docs,
in load order: source first, then distractors). 1350 cells, all hard negatives in [10,40] pages.
Related
Part of MUDDLE: Measuring Understanding of Documents under Distractor and Length Effects
(COLM 2026 Workshop on Context Beyond the Window).
