Refactor admin dashboard and standardize UI shells

src/TaxBaik.Web.Client/Components/Admin/Pages/TaxFilings/TaxFilingList.razor

@@ -10,18 +10,13 @@
 
 <PageTitle>신고 일정 관리</PageTitle>
 
-<section class="admin-page-hero">
-    <div>
-        <MudText Typo="Typo.caption" Class="admin-eyebrow">Tax Schedule</MudText>
-        <MudText Typo="Typo.h4" Class="admin-page-title">신고 일정</MudText>
-        <MudText Typo="Typo.body2" Class="admin-page-subtitle">고객별 세금 신고 마감일을 관리하고 완료 처리합니다.</MudText>
-    </div>
+<AdminPageHeader Title="신고 일정" Eyebrow="Tax Schedule" Subtitle="고객별 세금 신고 마감일을 관리하고 완료 처리합니다.">
     <MudButton Variant="Variant.Filled" Color="Color.Primary"
                OnClick="@(() => showAddForm = !showAddForm)"
                StartIcon="@Icons.Material.Filled.Add">
         일정 추가
     </MudButton>
-</section>
+</AdminPageHeader>
 
 @if (showAddForm)
 {