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/millisecondsToSeconds.mjs

@@ -0,0 +1,31 @@
+import { millisecondsInSecond } from "./constants.mjs";
+
+/**
+ * @name millisecondsToSeconds
+ * @category Conversion Helpers
+ * @summary Convert milliseconds to seconds.
+ *
+ * @description
+ * Convert a number of milliseconds to a full number of seconds.
+ *
+ * @param milliseconds - The number of milliseconds to be converted
+ *
+ * @returns The number of milliseconds converted in seconds
+ *
+ * @example
+ * // Convert 1000 miliseconds to seconds:
+ * const result = millisecondsToSeconds(1000)
+ * //=> 1
+ *
+ * @example
+ * // It uses floor rounding:
+ * const result = millisecondsToSeconds(1999)
+ * //=> 1
+ */
+export function millisecondsToSeconds(milliseconds) {
+  const seconds = milliseconds / millisecondsInSecond;
+  return Math.trunc(seconds);
+}
+
+// Fallback for modularized imports:
+export default millisecondsToSeconds;