Add post and event cards, shared calendar sheet and per-event ICS; rework past events and next-event card

Elternbeirat.Web/Features/Faqs/FaqList.razor

@@ -27,7 +27,7 @@ else
 {
     @foreach (var topic in _topics)
     {
-        <details class="faq-topic">
+        <details class="faq-topic disclosure">
             <summary>@topic.Title</summary>
             @if (!string.IsNullOrWhiteSpace(topic.Intro))
             {