Moppe cloud and canopy lighting across scale

Moppe now treats weather and forest cover as lighting representations across scale. Cloudiness consistently increases sky coverage and drives a 420 m projected, 1.6 by 0.8 m/s world-space cloud-transmission layer over terrain, ordinary world geometry, and water. Forest cover reuses its filtered canopy grain to attenuate direct and hemisphere light on the ground, clearing the footprint on trails, bases, snow, and submerged beds. This follows the near-tree plus distant shader-map decomposition: when crown geometry becomes subpixel, filtered ground radiance preserves canopy mass and shadow instead of emitting more triangles. The first noise-heavy shader prototype cost about 10% median GPU time across the 32-state feature benchmark; warped triangle waves and reuse of the existing canopy signal reduced the final median delta to 2.76%, with 0.57% in the fully enabled state. X9PHPN P6YBRN W8ZZWR