feat: redesign Exams List page to show submitted custom exams

- Added Custom Exams tab showing all exams from Generation page
- Displays title, module badges, duration, and status
- Added Create Exam button
- Kept Exam Sessions tab for institutional sessions
- Search filters across exams

Made-with: Cursor

node_modules/dom-helpers/esm/scrollParent.d.ts

@@ -0,0 +1,7 @@
+/**
+ * Find the first scrollable parent of an element.
+ *
+ * @param element Starting element
+ * @param firstPossible Stop at the first scrollable parent, even if it's not currently scrollable
+ */
+export default function scrollParent(element: HTMLElement, firstPossible?: boolean): Document | HTMLElement;