Add an E2E test for clicking all the way through the onboarding, restore code pane highlighting in onboarding (#2265)

* Add test clicking through each onboarding step

* Revert "get rid of code pane shit (#2259)"

This reverts commit d341681c0d.

* Fix the missing #code-pane id

* fmt

src/routes/Onboarding/InteractiveNumbers.tsx

@@ -15,11 +15,7 @@ export default function InteractiveNumbers() {
     <div className="fixed grid justify-end items-center inset-0 z-50 pointer-events-none">
       <div
         className="fixed inset-0 bg-black opacity-50 pointer-events-none"
-        style={
-          {
-            /*clipPath: useBackdropHighlight('code-pane')*/
-          }
-        }
+        style={{ clipPath: useBackdropHighlight('code-pane') }}
       ></div>
       <div
         className={