revert(layers): remove globe occlusion from ArcLayer

ArcLayer occlusion will be addressed separately. The depth buffer
handles most cases for arc geometry, and the segment boundary
artifacts need more investigation.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: chrisgervang

modules/layers/src/arc-layer/arc-layer-vertex.glsl.ts

@@ -224,12 +224,6 @@ void main(void) {
     arc.widthMinPixels, arc.widthMaxPixels
   );
 
-  // Hide arc segments that are occluded by the globe (on the back side)
-  // Set width to 0 instead of clipping to avoid artifacts at segment boundaries
-  if (project_globe_is_occluded(geometry.position.xyz)) {
-    widthPixels = 0.0;
-  }
-
   // extrude
   vec3 offset = vec3(
     getExtrusionOffset((next.xy - curr.xy) * indexDir, segmentSide, widthPixels),