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/concat-map/example/map.js

@@ -0,0 +1,6 @@
+var concatMap = require('../');
+var xs = [ 1, 2, 3, 4, 5, 6 ];
+var ys = concatMap(xs, function (x) {
+    return x % 2 ? [ x - 0.1, x, x + 0.1 ] : [];
+});
+console.dir(ys);