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/lodash/_root.js

@@ -0,0 +1,9 @@
+var freeGlobal = require('./_freeGlobal');
+
+/** Detect free variable `self`. */
+var freeSelf = typeof self == 'object' && self && self.Object === Object && self;
+
+/** Used as a reference to the global object. */
+var root = freeGlobal || freeSelf || Function('return this')();
+
+module.exports = root;