Revert "fix: soften cloud march edge"

This reverts commit 8884a77f7d.

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
         },
-        // Maximum raymarch length through the cloud deck, in world units.
-        // Too small creates a hard cloud-deck edge/ring near the horizon.
-        maxMarchUnits: 120,       // 30 was the old fixed cap
-        // maxMarchUnits: 60       // cheaper, but a harder far edge
         // Far softening reduces detail/noise at long view distances. Lower
         // max keeps the deck denser near the horizon and can remove the
         // transparent ring around the terrain edge.