Let the mouse wheel scroll the page over charts and the embedded radar

Chart zoom now needs Ctrl+scroll (or pinch); the embedded radar uses cooperative gestures.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

app/public/app.js

@@ -892,6 +892,9 @@ function createRadar(mapEl, timelineEl, playBtn, tsEl, layerBtn) {
     center: [-98.35, 39.5],
     zoom: 4,
     attributionControl: false,
+    // The embedded radar sits in a scrolling page: plain wheel / one-finger drag scroll the page,
+    // Ctrl+wheel / two fingers move the map.
+    cooperativeGestures: mapEl?.id === 'radar-embed',
   });
 
   let radarFrames = [];