feat(assets): add head template library and hair/eyebrow accessory GLBs
Adds the character head and hair accessory asset tiers:
HEAD TEMPLATES (client/assets/characters/heads/templates/)
4 head GLBs from Quaternius OnlyHead .blends:
head_001 (regular_f), head_002 (regular_m),
head_003 (teen_f), head_004 (teen_m)
Each paired with a 1024x1024 solid-white _mask.png (full-face tintable)
HAIR (client/assets/characters/hair/)
13 hairstyle GLBs + masks: bob, buns, cornrows, curly, long_wavy,
medium_wavy, pixie, ponytail, short_fade, short_messy, short_neat,
undercut, up_do; plus bald.glb placeholder
FACIAL HAIR (client/assets/characters/facial_hair/)
3 GLBs + masks: beard, moustache, mutton_chops
EYEBROWS (client/assets/characters/eyebrows/)
4 GLBs (no masks — tinted directly by shader):
female, regular, teen, thick
Masks are white (full coverage) pending future artist-authored greyscale
maps for per-region tinting. Eyebrows excluded per compositor spec.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>