replace custom data formatting w date-fns

package-lock.json

···
         "@tanstack/react-virtual": "^3.13.13",
         "actor-typeahead": "^0.1.2",
         "cookie": "^1.0.2",
+        "date-fns": "^4.1.0",
         "jose": "^6.1.0",
         "jszip": "^3.10.1",
         "lucide-react": "^0.544.0",
···
       "integrity": "sha512-M1uQkMl8rQK/szD0LNhtqxIPLpimGm8sOBwU7lLnCpSbTyY3yeU1Vc7l4KT5zT4s/yOxHH5O7tIuuLOCnLADRw==",
       "dev": true,
       "license": "MIT"
+    },
+    "node_modules/date-fns": {
+      "version": "4.1.0",
+      "resolved": "https://registry.npmjs.org/date-fns/-/date-fns-4.1.0.tgz",
+      "integrity": "sha512-Ukq0owbQXxa/U3EGtsdVBkR1w7KOQ5gIBqdH2hkvknzZPYvBxb/aa6E8L7tmjFtkwZBu3UXBbjIgPo/Ez4xaNg==",
+      "license": "MIT",
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/kossnocorp"
+      }
     },
     "node_modules/debug": {
       "version": "4.4.3",

package.json

···
     "@tanstack/react-virtual": "^3.13.13",
     "actor-typeahead": "^0.1.2",
     "cookie": "^1.0.2",
+    "date-fns": "^4.1.0",
     "jose": "^6.1.0",
     "jszip": "^3.10.1",
     "lucide-react": "^0.544.0",

src/components/HistoryTab.tsx

···
   userSettings,
   onLoadUpload,
 }: HistoryTabProps) {
-  const formatDate = (dateString: string) => {
-    const date = new Date(dateString);
-    return formatRelativeTime(date.toLocaleDateString("en-US"));
-  };
-
   return (
     <div className="p-6">
       {/* Setup Assistant Banner - Only show if wizard not completed */}
···
                       {upload.totalUsers === 1 ? "user found" : "users found"}
                     </Badge>
                     <Badge variant="info">
-                      Uploaded {formatDate(upload.createdAt)}
+                      Uploaded {formatRelativeTime(upload.createdAt)}
                     </Badge>
                   </div>
                 </div>

src/lib/utils/date.ts

···
+import { format, formatDistanceToNow } from "date-fns";
+
 export function formatDate(dateString: string): string {
   const date = new Date(dateString);
-  return date.toLocaleDateString("en-US", {
-    month: "short",
-    day: "numeric",
-    year: "numeric",
-    hour: "2-digit",
-    minute: "2-digit",
-  });
+  return format(date, "MMM d, yyyy, h:mm a");
 }
 
 export function formatRelativeTime(dateString: string): string {
   const date = new Date(dateString);
-  const now = new Date();
-  const diffMs = now.getTime() - date.getTime();
-  const diffMins = Math.floor(diffMs / 60000);
-  const diffHours = Math.floor(diffMs / 3600000);
-  const diffDays = Math.floor(diffMs / 86400000);
-
-  if (diffMins < 1) return "just now";
-  if (diffMins < 60) return `${diffMins}m ago`;
-  if (diffHours < 24) return `${diffHours}h ago`;
-  if (diffDays < 7) return `${diffDays}d ago`;
-
-  return formatDate(dateString);
+  return formatDistanceToNow(date, { addSuffix: true });
 }