Refactor admin dashboard and standardize UI shells

src/TaxBaik.Web.Client/Components/Admin/Pages/Announcements/AnnouncementEdit.razor

@@ -12,14 +12,9 @@
 
 <PageTitle>@(Id.HasValue ? "공지 수정" : "공지 등록")</PageTitle>
 
-<section class="admin-page-hero">
-    <div>
-        <MudText Typo="Typo.caption" Class="admin-eyebrow">Homepage</MudText>
-        <MudText Typo="Typo.h4" Class="admin-page-title">@(Id.HasValue ? "공지 수정" : "공지 등록")</MudText>
-    </div>
-</section>
+<AdminPageHeader Title="@(Id.HasValue ? "공지 수정" : "공지 등록")" Eyebrow="Homepage" />
 
-<MudPaper Class="admin-surface" Elevation="0">
+<AdminEditorPanel Loading="@isSaving" SkeletonContent="@null">
     <MudForm @ref="form">
         <MudGrid>
             <MudItem xs="12">
@@ -89,7 +84,7 @@
             </MudButton>
         </div>
     </MudForm>
-</MudPaper>
+</AdminEditorPanel>
 
 @code {
     [Parameter] public int? Id { get; set; }