clouds: retune weather coverage and make night follow weather

config.js

@@ -170,7 +170,9 @@ window.CONFIG = {
         // only ever reports sunny/cloudy/stormy, so the deck keeps that
         // coverage through the night as well - 'night' is used by the weather
         // simulation (weatherSim: true) alone.
-        density: { sunny: 0.30, cloudy: 0.70, stormy: 1.00, night: 0.45 },
+        density: { sunny: 0.25, cloudy: 0.50, stormy: 0.80 },
+        // 'night' intentionally has no own density: it follows the last
+        // non-night weather density (sunny/cloudy/stormy).
         // Cloud motion from Open-Meteo wind. Open-Meteo reports wind FROM
         // the reported compass direction; clouds advect toward the opposite
         // bearing. speedScale exaggerates real advection so the motion is
@@ -182,7 +184,7 @@ window.CONFIG = {
             // wind: { speedScale: 0 }         // static clouds
             // wind: { speedScale: 140, maxSpeed: 0.12 } // very visible motion
         }
-        // density: { sunny: 0.05, cloudy: 0.9, stormy: 1.0, night: 0.2 }
+        // density: { sunny: 0.05, cloudy: 0.9, stormy: 1.0 }
     },
 
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