1.0.93

fix: dither blocking buildings, not the selected one

Correct render order:
1. SelectedBuildingOutline pre-renders the selected building at
   renderOrder -1, filling the depth+color buffer first
2. BuildingMeshes renders all buildings with shader injection:
   blocking buildings (in front of selected, lateral < 4) get 50%
   screen-door dithering via interleaved gradient noise discard
3. Discarded fragments in blocking buildings reveal the selected
   building underneath (already in the framebuffer from step 1)
4. Gold outline renders normally on top

Simplified shader: no screen-space projection, no gradient radius,
no fresnel — just world-space blocking check + uniform dithering.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>