Pass 1 sphere-traces CultMath noise terrain (fbm plus Phacelle erosion) and the
world tree with a conservative Lipschitz step, writing colour and depth. Pass 2
marches fog and clouds only up to that depth at low resolution with TAA. The
camera pulls back from the tree on login. Vendors CultLib's generated GLSL
(658c09e). The Phacelle gradient bound is an empirical probe, not a proof.
Headless harness compiles, renders and times it; nothing run on a GPU.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
