Docs: bring GAME_DESIGN.md up to date, minor README consistency tweaks
GAME_DESIGN.md was ~100 commits behind: sphere brush with backface
rejection, spray, emission channel, camo/material sliders (runtime-only
persistence), radial pose menu + rendered pose icons, overview/escape
menu, rendering stack (HTrace WSGI / Deferred+, AVP shader URP ports,
lobby GI toggle), Poly Haven / ambientCG importers and misc editor
tools. README: radial pose menu + overview menu mentions.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
adminandClaude Fable 5
7240b82e9b