Refactor admin dashboard and standardize UI shells

src/TaxBaik.Web.Client/Components/Admin/Pages/Faqs/FaqEdit.razor

@@ -9,14 +9,10 @@
 
 <PageTitle>@(Id.HasValue ? "FAQ 수정" : "FAQ 등록")</PageTitle>
 
-<section class="admin-page-hero">
-    <div>
-        <MudText Typo="Typo.caption" Class="admin-eyebrow">홈페이지</MudText>
-        <MudText Typo="Typo.h4" Class="admin-page-title">@(Id.HasValue ? "FAQ 수정" : "FAQ 등록")</MudText>
-    </div>
+<AdminPageHeader Title="@(Id.HasValue ? "FAQ 수정" : "FAQ 등록")" Eyebrow="홈페이지">
     <MudButton Variant="Variant.Outlined" Href="/taxbaik/admin/faqs"
                StartIcon="@Icons.Material.Filled.ArrowBack">목록으로</MudButton>
-</section>
+</AdminPageHeader>
 
 <AdminEditorPanel Loading="@isLoading" SkeletonContent="@FaqSkeleton">
     <MudPaper Class="admin-surface" Elevation="0" Style="max-width:720px;">