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/secondsToMilliseconds.d.mts

@@ -0,0 +1,18 @@
+/**
+ * @name secondsToMilliseconds
+ * @category Conversion Helpers
+ * @summary Convert seconds to milliseconds.
+ *
+ * @description
+ * Convert a number of seconds to a full number of milliseconds.
+ *
+ * @param seconds - The number of seconds to be converted
+ *
+ * @returns The number of seconds converted in milliseconds
+ *
+ * @example
+ * // Convert 2 seconds into milliseconds
+ * const result = secondsToMilliseconds(2)
+ * //=> 2000
+ */
+export declare function secondsToMilliseconds(seconds: number): number;