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/fi.d.ts

@@ -0,0 +1,11 @@
+import type { Locale } from "./types.js";
+/**
+ * @category Locales
+ * @summary Finnish locale.
+ * @language Finnish
+ * @iso-639-2 fin
+ * @author Pyry-Samuli Lahti [@Pyppe](https://github.com/Pyppe)
+ * @author Edo Rivai [@mikolajgrzyb](https://github.com/mikolajgrzyb)
+ * @author Samu Juvonen [@sjuvonen](https://github.com/sjuvonen)
+ */
+export declare const fi: Locale;