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/math-intrinsics/isNegativeZero.js

@@ -0,0 +1,6 @@
+'use strict';
+
+/** @type {import('./isNegativeZero')} */
+module.exports = function isNegativeZero(x) {
+	return x === 0 && 1 / x === 1 / -0;
+};