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/@radix-ui/rect/dist/index.d.mts

@@ -0,0 +1,16 @@
+type Measurable = {
+    getBoundingClientRect(): DOMRect;
+};
+/**
+ * Observes an element's rectangle on screen (getBoundingClientRect)
+ * This is useful to track elements on the screen and attach other elements
+ * that might be in different layers, etc.
+ */
+declare function observeElementRect(
+/** The element whose rect to observe */
+elementToObserve: Measurable, 
+/** The callback which will be called when the rect changes */
+callback: CallbackFn): () => void;
+type CallbackFn = (rect: DOMRect) => void;
+
+export { type Measurable, observeElementRect };