enhance dashboard and user interface: update heading sizes, translate user label to German, and implement loan management features including fetching and displaying loans with error handling

admin/src/utils/userFuncs.ts

@@ -0,0 +1,14 @@
+export const formatDateTime = (value: string | null | undefined) => {
+  if (!value) return "N/A";
+  const inpDate = new Date(value);
+  if (isNaN(inpDate.getTime())) return "N/A";
+  return (
+    inpDate.toLocaleString(undefined, {
+      year: "numeric",
+      month: "2-digit",
+      day: "2-digit",
+      hour: "2-digit",
+      minute: "2-digit",
+    }) + " Uhr"
+  );
+};