refactor admin UX and stabilize shell

src/TaxBaik.Web.Client/Components/Admin/Pages/Faqs/FaqEdit.razor

@@ -2,7 +2,6 @@
 @page "/admin/faqs/{Id:int}/edit"
 @rendermode @(new InteractiveWebAssemblyRenderMode(prerender: false))
 @attribute [Authorize]
-@using TaxBaik.Web.Services
 @inject IFaqBrowserClient FaqClient
 @inject NavigationManager Navigation
 @inject ISnackbar Snackbar
@@ -15,7 +14,7 @@
 </AdminPageHeader>
 
 <AdminEditorPanel Loading="@isLoading" SkeletonContent="@FaqSkeleton">
-    <MudPaper Class="admin-surface" Elevation="0" Style="max-width:720px;">
+    <MudPaper Class="admin-surface admin-faq-edit-panel" Elevation="0">
         <MudForm @ref="form" @bind-IsValid="isValid">
             <MudGrid Spacing="3">
                 <MudItem xs="12">