Populate the elevation readout when the toggle is switched on

The effect cleared the readout when the toggle went off while the pointer was
stationary, but the symmetric case was unhandled: switching it on with the
cursor still showed nothing until the next mousemove. It now resolves once for
wherever the pointer already is.

Author: giswqs

packages/map/src/MapCanvas.tsx

@@ -1085,13 +1085,20 @@ export const MapCanvas = memo(function MapCanvas({
   // map (a keyboard-only toggle) would otherwise leave the last resolved value
   // on screen until the next mousemove.
   useEffect(() => {
-    if (showPointerElevation) return;
-    // invalidate() before clearing: a lookup scheduled inside the 500ms debounce
-    // window would otherwise still fire the request, and only be suppressed
-    // afterwards by the isEnabled() re-check. Cancelling the timer means the
-    // request is never made at all.
-    pointerElevationRef.current?.invalidate();
-    setPointerElevation(null);
+    if (!showPointerElevation) {
+      // invalidate() before clearing: a lookup scheduled inside the 500ms
+      // debounce window would otherwise still fire the request, and only be
+      // suppressed afterwards by the isEnabled() re-check. Cancelling the timer
+      // means the request is never made at all.
+      pointerElevationRef.current?.invalidate();
+      setPointerElevation(null);
+      return;
+    }
+    // Symmetrically, switching it *on* while the cursor sits still would show
+    // nothing until the next mousemove. Resolve once for wherever the pointer
+    // already is, so the readout appears with the toggle.
+    const coords = useAppStore.getState().pointerCoords;
+    if (coords) pointerElevationRef.current?.update(coords);
   }, [showPointerElevation, setPointerElevation]);
   const previousSelectedFeatureKey = useRef<string | null>(null);
   const previousDuckDBSelectionLayerId = useRef<string | null>(null);