Artifacts
What each model built on each task, shown on the held-out cases it was graded on.
Concrete frame
Hidden test buildings are the ones the reward is computed on (each model's best and median attempt); public dev buildings cover every attempt, but agents could test on them, so they are not graded. Each frame is the attempt's sizing program re-run, every column and beam drawn at its real section size and coloured by how close it is to its limit.