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; }

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

@@ -10,23 +10,20 @@
 
 <PageTitle>공지사항 관리</PageTitle>
 
-<section class="admin-page-hero">
-    <div>
-        <MudText Typo="Typo.caption" Class="admin-eyebrow">Homepage</MudText>
-        <MudText Typo="Typo.h4" Class="admin-page-title">공지사항 관리</MudText>
-        <MudText Typo="Typo.body2" Class="admin-page-subtitle">홈페이지 상단에 노출되는 공지사항을 등록하고 관리합니다.</MudText>
-    </div>
+<AdminPageHeader Title="공지사항 관리" Eyebrow="Homepage" Subtitle="홈페이지 상단에 노출되는 공지사항을 등록하고 관리합니다.">
     <MudButton Variant="Variant.Filled" Color="Color.Primary"
                StartIcon="@Icons.Material.Filled.Add"
                Href="/taxbaik/admin/announcements/create">
         공지 등록
     </MudButton>
-</section>
+</AdminPageHeader>
 
-<div class="d-flex pa-4 gap-4 align-center">
-    <MudTextField @bind-Value="searchQuery" Placeholder="공지사항 제목 검색..." Adornment="Adornment.Start" 
-                  AdornmentIcon="@Icons.Material.Filled.Search" IconSize="Size.Medium" Class="flex-grow-1" Immediate="true" Clearable="true" />
-</div>
+<AdminSearchBar>
+    <SearchContent>
+        <MudTextField @bind-Value="searchQuery" Placeholder="공지사항 제목 검색..." Adornment="Adornment.Start" 
+                      AdornmentIcon="@Icons.Material.Filled.Search" IconSize="Size.Medium" Class="flex-grow-1" Immediate="true" Clearable="true" />
+    </SearchContent>
+</AdminSearchBar>
 
 <AdminDataPanel Loading="@(announcements is null)" SkeletonContent="@AnnouncementSkeleton">
     @if (announcements is null)