feat: add member since date handling across admin and member views

src/pages/Dashboard.js

@@ -17,6 +17,7 @@ const Dashboard = () => {
   const [resendLoading, setResendLoading] = useState(false);
   const [eventActivity, setEventActivity] = useState(null);
   const [activityLoading, setActivityLoading] = useState(true);
+  const joinedDate = user?.member_since || user?.created_at;
 
   useEffect(() => {
     fetchUpcomingEvents();
@@ -197,7 +198,7 @@ const Dashboard = () => {
               <div>
                 <p className="text-sm text-brand-purple " style={{ fontFamily: "'Nunito Sans', sans-serif" }}>Member Since</p>
                 <p className="text-[var(--purple-ink)] font-medium" style={{ fontFamily: "'Nunito Sans', sans-serif" }}>
-                  {user?.created_at ? new Date(user.created_at).toLocaleDateString() : 'N/A'}
+                  {joinedDate ? new Date(joinedDate).toLocaleDateString() : 'N/A'}
                 </p>
               </div>
               {user?.subscription_start_date && user?.subscription_end_date && (