Group FAQs by a topic relation, ordered; drop unused FAQ teaser

Elternbeirat.Web/Features/Faqs/FaqList.razor

@@ -17,7 +17,7 @@ else
     @foreach (var group in _groups)
     {
         <section class="faq-topic">
-            <h2>@group.Key</h2>
+            <h2>@group.Key.Title</h2>
             @foreach (var faq in group)
             {
                 <details class="faq-item">

Elternbeirat.Web/Features/Faqs/FaqList.razor.cs

@@ -23,7 +23,7 @@ public partial class FaqList
     [CascadingParameter]
     private HttpContext? HttpContext { get; set; }
 
-    private IReadOnlyList<IGrouping<string, Faq>> _groups = [];
+    private IReadOnlyList<IGrouping<FaqTopic, Faq>> _groups = [];
 
     // Set when the content source could not be reached or read. The markup then
     // shows a "temporarily unavailable" note instead of "no questions", matching
@@ -35,7 +35,12 @@ public partial class FaqList
         try
         {
             var faqs = await PocketBase.GetFaqsAsync(HttpContext?.RequestAborted ?? CancellationToken.None);
-            _groups = [.. faqs.GroupBy(faq => faq.Topic)];
+
+            // GetFaqsAsync sorts by topic.order first, so grouping in encounter order
+            // keeps the topic groups in the order an editor gave the topics. Entries
+            // without an expanded topic have no group and are skipped rather than
+            // grouped under a null heading.
+            _groups = [.. faqs.Where(faq => faq.Topic is not null).GroupBy(faq => faq.Topic!)];
         }
         catch (PocketBaseUnavailableException exception)
         {