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/react-focus-guards/dist/index.d.ts

@@ -0,0 +1,13 @@
+import * as React from 'react';
+
+interface FocusGuardsProps {
+    children?: React.ReactNode;
+}
+declare function FocusGuards(props: FocusGuardsProps): React.ReactNode;
+/**
+ * Injects a pair of focus guards at the edges of the whole DOM tree
+ * to ensure `focusin` & `focusout` events can be caught consistently.
+ */
+declare function useFocusGuards(): void;
+
+export { FocusGuards, FocusGuards as Root, useFocusGuards };