C++/raylib semi-realistic fantasy/sci-fi planet generator on a fixed icosphere
grid (Eulerian: properties flow over fixed cells). World-creation stages:
tectonics, continental drift & erosion, hydrology (rivers/lakes), climate
(temperature + orographic precipitation), and biome classification. Engine in
src/sim (raylib-free, headless-testable), viewer in src/render. See CLAUDE.md
and docs/ (design-notes.md, fauna-flora-plan.md = next step).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>