Brings the full animal foundation onto main and folds its new defs into the
Defs/ subfolder layout introduced on main:
- animal genes -> Defs/Genes/Animal.json (split out of genes.json)
- animals/bodies/hediffs/needs/thoughts -> own Defs/<Type>/ subfolders
- ProductMeat/Bone/Leather + bigger world presets auto-merged via rename detection
- PawnDef un-sealed (AnimalDef : PawnDef); def-location doc comments updated to subfolders
- engine pointer kept at main's newer 96e19c7 (only adds directional sun shadows)
Build + --check-content clean: 11 def types, 33 genes, 35 plants, 32 traits.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
