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/date-fns/locale/lt.d.mts

@@ -0,0 +1,10 @@
+import type { Locale } from "./types.js";
+/**
+ * @category Locales
+ * @summary Lithuanian locale.
+ * @language Lithuanian
+ * @iso-639-2 lit
+ * @author Pavlo Shpak [@pshpak](https://github.com/pshpak)
+ * @author Eduardo Pardo [@eduardopsll](https://github.com/eduardopsll)
+ */
+export declare const lt: Locale;