Use class-only grid activation in event filter

contao/templates/frontend/event_filter.html.twig

@@ -47,11 +47,23 @@
     const targetEventListId = filters.dataset.eventlistId || 'eventlist';
     const list = document.getElementById(targetEventListId);
 
-    if (!list) {
-        console.warn(`[event_filter] Target event list #${targetEventListId} was not found.`);
+    const applyDefaultGrid = (targetList) => {
+        if (!targetList) {
+            return;
         }
 
-    list?.classList.add('event-filter-target-list');
+        targetList.classList.add('event-filter-target-list');
+        targetList.classList.add('grid');
+    };
+
+    if (!list) {
+        console.warn(`[event_filter] Target event list #${targetEventListId} was not found.`);
+        window.addEventListener('DOMContentLoaded', () => {
+            applyDefaultGrid(document.getElementById(targetEventListId));
+        }, { once: true });
+    }
+
+    applyDefaultGrid(list);
 
     const events = list ? Array.from(list.querySelectorAll(':scope > .event')) : [];
     const tagSelect = filters.querySelector('#tag-filter');