Format event date as DD.MM.YYYY on the dashboard.

Updated the event date formatting logic to display dates in the DD.MM.YYYY format (used in the RSVP section). This improves consistency and aligns with user expectations for date representation.

frontend/src/app/(main)/dashboard/events/[slug]/page.tsx

@@ -177,7 +177,13 @@ export default function EventDetailPage() {
                       className="bg-yellow-50 text-yellow-700 border-yellow-200"
                     >
                       RSVP by{" "}
-                      {new Date(event.rsvp_deadline).toLocaleDateString()}
+                      {new Date(event.event_date)
+                        .toLocaleDateString("en-GB", {
+                          day: "2-digit",
+                          month: "2-digit",
+                          year: "numeric",
+                        })
+                        .replace(/\//g, ".")}
                     </Badge>
                   </div>
                 )}