Fix page scrolling when using mouse wheel to zoom in Jupyter notebooks (#194)

Adds a wheel event listener that prevents event propagation to the parent
page while still allowing HiGlass to handle zoom interactions. This fixes
the issue where scrolling to zoom in the HiGlass widget would also scroll
the Jupyter notebook page, particularly when running notebooks in VS Code.

The fix uses stopPropagation() with passive: false to intercept wheel
events at the widget container level before they bubble up to the notebook.

Author: kaspermunch

src/higlass/widget.js

@@ -273,6 +273,12 @@ function addEventListenersTo(el) {
     signal: controller.signal,
   });
 
+  // prevent wheel events from scrolling the page while allowing HiGlass zoom
+  el.addEventListener("wheel", (event) => event.stopPropagation(), {
+    signal: controller.signal,
+    passive: false,
+  });
+
   return () => controller.abort();
 }