factor: Switch to Web Mercator coordinates

ui/src/App.vue

@@ -188,6 +188,14 @@ export default {
       });
       if (renderer) renderer.render(scene, camera);
     };
+    
+    // Convert lat/lon to Web Mercator meters (EPSG:3857)
+    const lonLatToWebMercator = (lon, lat) => {
+      const x = lon * 20037508.34 / 180;
+      let y = Math.log(Math.tan((90 + lat) * Math.PI / 360)) / (Math.PI / 180);
+      y = y * 20037508.34 / 180;
+      return { x, y };
+    };
 
     const initThreeJS = () => {
       scene = new THREE.Scene();
@@ -230,10 +238,14 @@ export default {
       const ne = bounds.getNorthEast();
       const sw = bounds.getSouthWest();
       
-      camera.left = sw.lng;
-      camera.right = ne.lng;
-      camera.top = ne.lat;
-      camera.bottom = sw.lat;
+      // Convert lat/lon bounds to Web Mercator meters
+      const neMerc = lonLatToWebMercator(ne.lng, ne.lat);
+      const swMerc = lonLatToWebMercator(sw.lng, sw.lat);
+      
+      camera.left = swMerc.x;
+      camera.right = neMerc.x;
+      camera.top = neMerc.y;
+      camera.bottom = swMerc.y;
       camera.updateProjectionMatrix();
       
       renderer.render(scene, camera);