atmosphere: remove volumetric fog pass

config.js

@@ -307,12 +307,7 @@ window.CONFIG = {
         airGain: 0.55,            // Rayleigh airlight strength (blue-biased)
         distanceFog: false,       // legacy aerial perspective is off
         model: {
-            enabled: true,
+            enabled: false        // volumetric atmosphere/fog removed
-            heightKm: 35.0,       // full atmosphere shell around the planet
-            scaleHeightKm: 8.5,   // density falls exponentially with altitude
-            density: 0.12,        // base optical density
-            grayTau: 1.5,         // high optical depth becomes grey fog
-            gain: 2.0             // scattering brightness
         },
         hazeResidual: 0.30,       // surface colour surviving at the full fog distance
         cloudBrightness: 1.0,     // cloud albedo (theme hue, brightness from the model)

vendor/clouds3d.js

@@ -2141,7 +2141,7 @@ var ATMO_HAZE_RESIDUAL = (typeof ATMO.hazeResidual === 'number')
     ? Math.max(0.02, Math.min(0.95, ATMO.hazeResidual)) : 0.30;
 var ATMO_DISTANCE_FOG = ATMO.distanceFog !== false;
 var ATMO_MODEL = ATMO.model || {};
-var ATMO_MODEL_ON = ATMO_MODEL.enabled !== false;
+var ATMO_MODEL_ON = ATMO_MODEL.enabled === true;
 var ATMO_MODEL_HEIGHT_KM = (typeof ATMO_MODEL.heightKm === 'number')
     ? Math.max(1.0, Math.min(80.0, ATMO_MODEL.heightKm)) : 35.0;
 var ATMO_MODEL_HEIGHT_UNITS = ATMO_MODEL_HEIGHT_KM / KM_PER_TILE;