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/react-remove-scroll/dist/es2015/pinchAndZoom.d.ts

@@ -0,0 +1,8 @@
+import { Touch } from 'react';
+export declare const pinchOrZoom: (event: TouchEvent, cache: Record<number, Touch>) => false | {
+    action: string;
+    coords?: undefined;
+} | {
+    action: string;
+    coords: number[];
+};