clouds: advect cloud field with Open-Meteo wind

config.js

@@ -152,7 +152,16 @@ 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: 0.30, cloudy: 0.70, stormy: 1.00, night: 0.45 },
+        // 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
+        // visible at the world scale (1 unit ~ 12.9 km).
+        wind: {
+            speedScale: 80,
+            minSpeed: 0.004,
+            maxSpeed: 0.08
+        }
         // density: { sunny: 0.05, cloudy: 0.9, stormy: 1.0, night: 0.2 }
     },