fix(admin): remove drawer footer info and close on mobile

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

@@ -83,24 +83,6 @@
             <MudNavLink Href="/taxbaik/admin/inquiries" Icon="@Icons.Material.Filled.Forum">문의 관리</MudNavLink>
             <MudNavLink Href="/taxbaik/admin/settings" Icon="@Icons.Material.Filled.Tune">설정</MudNavLink>
         </MudNavMenu>
-        <div class="admin-drawer-footer">
-            <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>
 
     <MudMainContent Class="admin-main">
@@ -121,6 +103,16 @@
         Navigation.LocationChanged += OnLocationChanged;
     }
 
+    protected override async Task OnAfterRenderAsync(bool firstRender)
+    {
+        if (!firstRender)
+            return;
+
+        var viewportWidth = await JS.InvokeAsync<int>("taxbaikAdminSession.getViewportWidth");
+        drawerOpen = viewportWidth >= 960;
+        StateHasChanged();
+    }
+
     private void OnLocationChanged(object? sender, LocationChangedEventArgs args)
     {
         _ = InvokeAsync(() => JS.InvokeVoidAsync("taxbaikAdminSession.showLoading"));

TaxBaik.Web/wwwroot/js/admin-session.js

@@ -5,6 +5,10 @@ window.taxbaikAdminSession = {
             window.location.pathname.toLowerCase().endsWith('/admin/login'));
     },
 
+    getViewportWidth: function () {
+        return window.innerWidth || document.documentElement.clientWidth || 0;
+    },
+
     clearAuthToken: function () {
         try {
             localStorage.removeItem('auth_token');