Harden admin telemetry and deployment safeguards

TaxBaik.Web/Components/Admin/Pages/Announcements/AnnouncementList.razor

@@ -27,10 +27,9 @@
                   AdornmentIcon="@Icons.Material.Filled.Search" IconSize="Size.Medium" Class="flex-grow-1" Immediate="true" Clearable="true" />
 </div>
 
-<MudPaper Class="admin-surface" Elevation="0">
+<AdminDataPanel Loading="@(announcements is null)" SkeletonContent="@AnnouncementSkeleton">
     @if (announcements is null)
     {
-        <MudProgressLinear Indeterminate="true" />
     }
     else if (!FilteredAnnouncements.Any())
     {
@@ -98,7 +97,7 @@
             검색 결과 @(FilteredAnnouncements.Count())개 · 총 @(announcements.Count)개
         </MudText>
     }
-</MudPaper>
+</AdminDataPanel>
 
 @code {
     [CascadingParameter]
@@ -107,6 +106,14 @@
     private List<Announcement>? announcements;
     private string searchQuery = "";
 
+    private RenderFragment AnnouncementSkeleton => builder =>
+    {
+        builder.OpenComponent<AdminSkeletonRows>(0);
+        builder.AddAttribute(1, "Rows", 5);
+        builder.AddAttribute(2, "Columns", 4);
+        builder.CloseComponent();
+    };
+
     private IEnumerable<Announcement> FilteredAnnouncements => announcements?
         .Where(a => string.IsNullOrEmpty(searchQuery) || 
                     a.Title.Contains(searchQuery, StringComparison.OrdinalIgnoreCase))