Refactor admin dashboard and standardize UI shells

src/TaxBaik.Web.Client/Components/Admin/Pages/Clients/ClientDetail.razor

@@ -11,13 +11,7 @@
 
 <PageTitle>고객 상세</PageTitle>
 
-<section class="admin-page-hero">
-    <div>
-        <MudText Typo="Typo.caption" Class="admin-eyebrow">Client Details</MudText>
-        <MudText Typo="Typo.h4" Class="admin-page-title">고객 상세</MudText>
-        <MudText Typo="Typo.body2" Class="admin-page-subtitle">고객 정보와 상담 이력을 관리합니다.</MudText>
-    </div>
-</section>
+<AdminPageHeader Title="고객 상세" Eyebrow="Client Details" Subtitle="고객 정보와 상담 이력을 관리합니다." />
 
 @if (client == null)
 {

src/TaxBaik.Web.Client/Components/Admin/Pages/Clients/ClientEdit.razor

@@ -12,14 +12,10 @@
 
 <PageTitle>@(Id.HasValue ? "고객 수정" : "고객 등록")</PageTitle>
 
-<section class="admin-page-hero">
-    <div>
-        <MudText Typo="Typo.caption" Class="admin-eyebrow">CRM</MudText>
-        <MudText Typo="Typo.h4" Class="admin-page-title">@(Id.HasValue ? "고객 수정" : "고객 등록")</MudText>
-    </div>
+<AdminPageHeader Title="@(Id.HasValue ? "고객 수정" : "고객 등록")" Eyebrow="CRM">
     <MudButton Variant="Variant.Outlined" Href="/taxbaik/admin/clients"
                StartIcon="@Icons.Material.Filled.ArrowBack">목록으로</MudButton>
-</section>
+</AdminPageHeader>
 
 <AdminEditorPanel Loading="@isLoading" SkeletonContent="@ClientEditSkeleton">
     @if (isLoading)

src/TaxBaik.Web.Client/Components/Admin/Pages/Clients/ClientList.razor

@@ -21,24 +21,24 @@
 </AdminPageHeader>
 
 @* 검색/필터 바 *@
-<MudPaper Class="admin-surface mb-3 pa-3" Elevation="0">
-    <MudGrid>
-        <MudItem xs="12" md="5">
-            <MudTextField @bind-Value="searchText" Label="검색 (이름·연락처·회사명)"
-                          Adornment="Adornment.End" AdornmentIcon="@Icons.Material.Filled.Search"
-                          Immediate="false" OnKeyUp="@OnSearchKeyUp" />
-        </MudItem>
-        <MudItem xs="12" md="3">
-            <CommonCodeSelect @bind-Value="statusFilter" Group="CLIENT_STATUS" Label="상태" Placeholder="전체" Clearable="true" />
-        </MudItem>
-        <MudItem xs="12" md="2" Class="d-flex align-center">
-            <MudButton Variant="Variant.Outlined" OnClick="@SearchAsync" FullWidth="true">검색</MudButton>
-        </MudItem>
-        <MudItem xs="12" md="2" Class="d-flex align-center">
-            <MudButton Variant="Variant.Text" OnClick="@ResetAsync" FullWidth="true">초기화</MudButton>
-        </MudItem>
-    </MudGrid>
-</MudPaper>
+<AdminSearchBar>
+    <SearchContent>
+        <MudGrid>
+            <MudItem xs="12" md="5">
+                <MudTextField @bind-Value="searchText" Label="검색 (이름·연락처·회사명)"
+                              Adornment="Adornment.End" AdornmentIcon="@Icons.Material.Filled.Search"
+                              Immediate="false" OnKeyUp="@OnSearchKeyUp" />
+            </MudItem>
+            <MudItem xs="12" md="3">
+                <CommonCodeSelect @bind-Value="statusFilter" Group="CLIENT_STATUS" Label="상태" Placeholder="전체" Clearable="true" />
+            </MudItem>
+        </MudGrid>
+    </SearchContent>
+    <Actions>
+        <MudButton Variant="Variant.Outlined" OnClick="@SearchAsync">검색</MudButton>
+        <MudButton Variant="Variant.Text" OnClick="@ResetAsync">초기화</MudButton>
+    </Actions>
+</AdminSearchBar>
 
 <AdminDataPanel Loading="@(clients is null)" SkeletonContent="@ClientListSkeleton">
     @if (clients is null)