GroundOcclusionUniforms

What a shader needs to ask whether the ground hides a G-buffer surface: the C++ mirror of `struct GroundOcclusion` in construct/shaders/GroundPlane.glsl, byte for byte (std140).

Declared in src/libs/libconstruct/construct/rendering/GroundOcclusion.hpp.

Detailed description

GroundPlane::occlusionUniforms() fills it. The selection and the hover highlight carry it at the end of their uniform blocks, so they do not draw over the part of a model that the ground hides (2026-10-16). All zero means "no ground".