fix(web): add try/finally, concurrency guard, accessible label, registration link to showcase

src/GmRelay.Web/Components/Pages/Showcase.razor

@@ -36,8 +36,8 @@
     </div>
 
     <div class="showcase-filter-group">
-        <span class="showcase-filter-label">Система</span>
-        <select class="gm-form-control showcase-filter-select" @onchange="OnSystemChanged">
+        <label class="showcase-filter-label" for="system-filter">Система</label>
+        <select id="system-filter" class="gm-form-control showcase-filter-select" aria-label="Система" @onchange="OnSystemChanged">
             <option value="" selected="@(filter.System is null)">Любая</option>
             @foreach (var system in Enum.GetValues<GameSystem>())
             {
@@ -134,7 +134,7 @@ else
                         <a class="btn-gm btn-gm-outline" href="@($"/s/{session.Id}")">Подробнее</a>
                         @if (session.AllowDirectRegistration)
                         {
-                            <button class="btn-gm btn-gm-primary">Записаться</button>
+                            <a class="btn-gm btn-gm-primary" href="@($"/s/{session.Id}?register=1")">Записаться</a>
                         }
                     </div>
                 </div>
@@ -318,22 +318,37 @@ else
     private async Task LoadAsync()
     {
         loading = true;
-        page = 1;
-        sessions.Clear();
-        var results = await SessionStore.GetShowcaseSessionsAsync(filter, page, PageSize);
-        sessions.AddRange(results);
-        hasMore = results.Count == PageSize;
-        loading = false;
+        try
+        {
+            page = 1;
+            sessions.Clear();
+            var results = await SessionStore.GetShowcaseSessionsAsync(filter, page, PageSize);
+            sessions.AddRange(results);
+            hasMore = results.Count == PageSize;
+        }
+        finally
+        {
+            loading = false;
+        }
     }
 
     private async Task LoadMoreAsync()
     {
+        if (loading)
+            return;
+
         loading = true;
-        page++;
-        var results = await SessionStore.GetShowcaseSessionsAsync(filter, page, PageSize);
-        sessions.AddRange(results);
-        hasMore = results.Count == PageSize;
-        loading = false;
+        try
+        {
+            page++;
+            var results = await SessionStore.GetShowcaseSessionsAsync(filter, page, PageSize);
+            sessions.AddRange(results);
+            hasMore = results.Count == PageSize;
+        }
+        finally
+        {
+            loading = false;
+        }
     }
 
     private async Task OnFilterChanged()