Directory structure, naming conventions, segmentation spec, and import pipeline for the 11 body type / 21 segment character system. Covers Quaternius Source tier mapping, CharacterVisualDescriptor contract, Surface Deform batch clothing pipeline, and coverage.json format. Built from spike findings with all meshes starting fresh from Source .blend files. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>