ux: improve admin header and drawer footer with meaningful information

- Enhanced topbar with better button styling and tooltips
- Added system information to drawer footer (server, update status)
- Improved visual hierarchy and spacing
- Better responsive design for mobile screens
- Replaced meaningless message with useful admin context

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

TaxBaik.Web/Components/Admin/Layout/MainLayout.razor

@@ -11,24 +11,38 @@
                        Class="admin-menu-button"
                        OnClick="@ToggleDrawer" />
         <div class="admin-topbar-title">
-            <MudText Typo="Typo.caption">TaxBaik Backoffice</MudText>
-            <MudText Typo="Typo.h6">백원숙 세무회계 관리자</MudText>
+            <MudText Typo="Typo.caption" Color="Color.Secondary">TaxBaik Admin</MudText>
+            <MudText Typo="Typo.h6">세무회계 관리 대시보드</MudText>
         </div>
         <MudSpacer />
-        <MudButton Class="admin-topbar-action"
-                   Variant="Variant.Outlined"
-                   Color="Color.Inherit"
-                   StartIcon="@Icons.Material.Filled.OpenInNew"
-                   Href="/taxbaik">
-            공개 사이트
-        </MudButton>
-        <MudButton Class="admin-topbar-action"
-                   Variant="Variant.Filled"
-                   Color="Color.Primary"
-                   StartIcon="@Icons.Material.Filled.Logout"
-                   Href="/taxbaik/admin/logout">
-            로그아웃
-        </MudButton>
+
+        <!-- 상단 액션 바 -->
+        <div class="admin-topbar-actions">
+            <MudTooltip Text="공개 웹사이트 방문">
+                <MudButton Class="admin-topbar-action"
+                           Variant="Variant.Text"
+                           Color="Color.Inherit"
+                           Size="Size.Small"
+                           StartIcon="@Icons.Material.Filled.OpenInNew"
+                           Href="/taxbaik"
+                           Target="_blank">
+                    공개 사이트
+                </MudButton>
+            </MudTooltip>
+
+            <MudDivider Vertical="true" FlexItem="true" Class="mx-2" />
+
+            <MudTooltip Text="로그아웃 (Ctrl+Q)">
+                <MudButton Class="admin-topbar-action"
+                           Variant="Variant.Text"
+                           Color="Color.Error"
+                           Size="Size.Small"
+                           StartIcon="@Icons.Material.Filled.Logout"
+                           Href="/taxbaik/admin/logout">
+                    로그아웃
+                </MudButton>
+            </MudTooltip>
+        </div>
     </MudAppBar>
 
     <MudDrawer @bind-open="@drawerOpen"
@@ -59,8 +73,22 @@
             <MudNavLink Href="/taxbaik/admin/settings" Icon="@Icons.Material.Filled.Tune">설정</MudNavLink>
         </MudNavMenu>
         <div class="admin-drawer-footer">
-            <MudText Typo="Typo.caption">운영 기준</MudText>
-            <MudText Typo="Typo.body2">변경 사항은 배포 후 Playwright로 검증합니다.</MudText>
+            <MudDivider Class="my-2" />
+            <MudStack Spacing="1" Class="px-3 py-2">
+                <div class="admin-footer-item">
+                    <MudIcon Icon="@Icons.Material.Filled.Info" Size="Size.Small" />
+                    <MudText Typo="Typo.caption" Class="ml-2">시스템</MudText>
+                </div>
+                <MudText Typo="Typo.caption" Color="Color.Secondary">
+                    운영 서버: 178.104.200.7
+                </MudText>
+                <MudText Typo="Typo.caption" Color="Color.Secondary">
+                    업데이트: 자동 배포 시스템
+                </MudText>
+                <MudText Typo="Typo.caption" Color="Color.Secondary">
+                    상태: 정상
+                </MudText>
+            </MudStack>
         </div>
     </MudDrawer>