Port proven shaders (toon, toon_masked, outline) and skin tone textures
from quaternius-aesthetic spike to production client. Import 65-bone
armature and Universal Animation Libraries (UAL1 + UAL2). Set
gltf/embedded_image_handling=3 in project.godot (critical import setting).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>