Revert "feat: wait for terrain before drawing clouds"

This reverts commit 8cca47f86e.

config.js

@@ -335,10 +335,6 @@ window.CONFIG = {
             start: 0.35,          // world units: clouds fade out very close to camera
             end: 2.5              // full density from this distance onward
         },
-        // Delay the volumetric cloud pass until the DEM/terrain mesh is
-        // ready. This avoids clouds appearing over an unfinished ground model.
-        waitForTerrain: true,     // false = draw clouds immediately
-        // waitForTerrain: false
         // Terrain occlusion for clouds. false draws clouds in front of the
         // terrain mesh even when terrain is closer; true clips cloud rays
         // against the terrain distance buffer.