fix: correct admin render mode to use WebAssembly with proper assembly reference

Revert to InteractiveWebAssemblyRenderMode for App.razor as required by validation script.
Add back AddInteractiveWebAssemblyComponents and AddInteractiveWebAssemblyRenderMode.
Fix assembly reference to use TaxBaik.WasmClient._Imports (RootNamespace of TaxBaik.Web.Client project).

This mixed render mode architecture allows:
- App.razor: WebAssembly shell for client-side routing
- Login.razor: Server-side prerender for authentication

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

TaxBaik.Web/Components/Admin/App.razor

@@ -37,7 +37,7 @@
         </div>
     </div>
     <MudThemeProvider @bind-IsDarkMode="isDarkMode" Theme="mudTheme" />
-    <Routes @rendermode="new InteractiveServerRenderMode(prerender: true)" />
+    <Routes @rendermode="new InteractiveWebAssemblyRenderMode(prerender: true)" />
     <script src="/taxbaik/_content/MudBlazor/MudBlazor.min.js"></script>
     <script src="/taxbaik/js/admin-session.js"></script>
     <script src="/taxbaik/_framework/blazor.web.js"></script>

TaxBaik.Web/Program.cs

@@ -71,10 +71,11 @@ builder.Services.AddRateLimiter(options =>
     });
 });
 
-// Razor Pages + Blazor Server 통합
+// Razor Pages + Blazor Server/WebAssembly 통합
 builder.Services.AddRazorPages();
 builder.Services.AddRazorComponents()
-    .AddInteractiveServerComponents();
+    .AddInteractiveServerComponents()
+    .AddInteractiveWebAssemblyComponents();
 builder.Services.Configure<Microsoft.AspNetCore.Components.Server.CircuitOptions>(options =>
 {
     options.DetailedErrors = true;
@@ -390,6 +391,8 @@ app.MapStaticAssets();
 // 인증은 Blazor AuthorizeRouteView → RedirectToLogin 에서 처리한다.
 app.MapRazorComponents<TaxBaik.Web.Components.Admin.App>()
    .AddInteractiveServerRenderMode()
+   .AddInteractiveWebAssemblyRenderMode()
+   .AddAdditionalAssemblies(typeof(TaxBaik.WasmClient._Imports).Assembly)
    .AllowAnonymous();
 
 // 애플리케이션 시작/종료 로깅