Restore 8acfc94e for impact-reg-konfai 1.8.6

Give each layer its receptive field in models.json, and keep one DINOv2 model

Let the 2D DINOv2 and SAM 2.1 models take slices of any size

Script the DINOv2 wrapper so it keeps its defaults and reads the statistics it is passed

Move input normalization to models and make layer selection part of forward()