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/symbol-tree/lib/TreePosition.js

@@ -0,0 +1,11 @@
+'use strict';
+
+/* eslint-disable sort-keys */
+module.exports = Object.freeze({
+        // same as DOM DOCUMENT_POSITION_
+        DISCONNECTED: 1,
+        PRECEDING: 2,
+        FOLLOWING: 4,
+        CONTAINS: 8,
+        CONTAINED_BY: 16,
+});