fix: add WASM boot timeout to forcefully hide loading overlay

PROBLEM: 대시보드 페이지에서 로딩 오버레이가 3분 이상 표시됨
- AdminShell은 렌더됨 (일부 WASM 로드)
- 하지만 hideLoading() 호출 지연 또는 미호출

SOLUTION: App.razor에 30초 타임아웃 추가
- WASM 부팅이 30초 초과하면 강제로 hideLoading() 호출
- 사용자 경험 개선 (최대 30초 로딩)

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

src/TaxBaik.Web/Program.cs

@@ -12,13 +12,14 @@ using Microsoft.AspNetCore.ResponseCompression;
 using Microsoft.IdentityModel.Tokens;
 using MudBlazor.Services;
 using Serilog;
+using FastEndpoints;
 using System.Threading.RateLimiting;
 using TaxBaik.Application;
 using TaxBaik.Application.Services;
 using TaxBaik.Application.Utils;
 using TaxBaik.Infrastructure;
 using TaxBaik.Web.Services;
-using TaxBaik.Web.Services.AdminClients;
+using TaxBaik.Web.Components.Admin.Services.AdminClients;
 
 var builder = WebApplication.CreateBuilder(args);
 var isProduction = builder.Environment.IsProduction();