Update zoom functionality in app.js to ensure world transformation is applied during zoom operations

- Added a call to `updateWorldTransform()` in the `flushZoomVisuals()` function to maintain visual consistency.
- Removed redundant call to `updateWorldTransform()` in the `applyZoom()` function, streamlining the zoom process.

app.js

@@ -478,6 +478,7 @@
   function flushZoomVisuals() {
     zoomVisualRaf = 0
     if (!svg || SCALE <= 0) return
+    updateWorldTransform()
     rebuildWorldSvg()
   }
 
@@ -489,7 +490,6 @@
     var factor = delta > 0 ? 1.12 : 1 / 1.12
     zoomLevel = Math.max(0.3, Math.min(8, zoomLevel * factor))
     SCALE = viewportMaxCornerPx() / BASE_VIEW_RADIUS_KM * zoomLevel
-    updateWorldTransform()
     scheduleZoomVisuals()
     updateZoomLabel()
   }