Replaces the upreza-derived 4K dungeon textures + AtlasLoot boss-coord
overlay (which had a consistent positional offset against texture skulls)
with keystone.guru's z=4 tile pyramid stitched to 6144x4096 WebP per floor.
kg's split_floors.js gives per-dungeon enemies, packs (polygons), patrols
(polylines), and map icons calibrated to those tiles, so overlays align
pixel-perfectly. 27/29 classic dungeons now have full enemy/pack data;
ZG + Sunken Temple have maps only.
Pipeline: tools/kg_fetch.py -> tools/kg_stitch.py -> tools/kg_build_data.py.