Minecraft static mob-model rollout

Selected models and textures from Mineclonia mobs_mc contributors.
https://codeberg.org/mineclonia/mineclonia
Pinned revision: 5258bf22599f0d9ca4cf7dad258acc0a91bdb23a
Pinned release: 0.123.0 / ContentDB 37652
Archive SHA-256: 3f2255d5dffcff44d726e38f64a8362932281fb270976c753be375bdcc1aa1fa

Models by 22i are GPLv3. Exact upstream B3D sources accompany the
offline static-geometry adaptations under source/. Textures have
file-specific terms recorded in LICENSE-media.md; the selected textures
are Pixel Perfection derivatives under CC BY-SA 4.0 unless that record
states otherwise. README.md and CREDITS.md preserve contributor credits.

The rollout extracts the reviewed visible base-texture surface from the first
model mesh in its standing pose, mirrors its Z axis for the browser,
centers it, and normalizes its largest dimension to 1.5 world units.
It does not copy animation code or empty equipment/overlay surfaces.