Fix back button cycling in Telegram Mini App

Add replace: true to all navigate() calls in useBackButton hooks
Prevents history cycles when navigating back and forth
All 32 admin pages now use navigate(path, { replace: true })
Back button now goes directly to parent without cycling

src/pages/AdminUsers.tsx

@@ -399,7 +399,7 @@ export default function AdminUsers() {
   const { capabilities } = usePlatform();
 
   // Use native Telegram back button in Mini App
-  useBackButton(() => navigate('/admin'));
+  useBackButton(() => navigate('/admin', { replace: true }));
 
   const [users, setUsers] = useState<UserListItem[]>([]);
   const [stats, setStats] = useState<UsersStatsResponse | null>(null);