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/zh-CN.d.ts

@@ -0,0 +1,13 @@
+import type { Locale } from "./types.js";
+/**
+ * @category Locales
+ * @summary Chinese Simplified locale.
+ * @language Chinese Simplified
+ * @iso-639-2 zho
+ * @author Changyu Geng [@KingMario](https://github.com/KingMario)
+ * @author Song Shuoyun [@fnlctrl](https://github.com/fnlctrl)
+ * @author sabrinaM [@sabrinamiao](https://github.com/sabrinamiao)
+ * @author Carney Wu [@cubicwork](https://github.com/cubicwork)
+ * @author Terrence Lam [@skyuplam](https://github.com/skyuplam)
+ */
+export declare const zhCN: Locale;