fix: correct middleware pipeline order - CRITICAL

URGENT FIX:
The request reached the end of the pipeline without executing the endpoint

Root cause:
- UseBlazorFrameworkFiles was positioned AFTER UseRouting
- This caused WASM files to not be intercepted properly
- Result: 500 error on all requests, admin login completely broken

Solution:
Correct order (ASP.NET Core pipeline):
1. UsePathBase
2. UseResponseCompression
3. UseBlazorFrameworkFiles (WASM files) ← MUST be BEFORE UseRouting
4. UseStaticFiles (static assets)
5. UseSession
6. UseRouting ← Now in correct position
7. UseExceptionHandler
8. UseRateLimiter, UseAuthentication, UseAuthorization, UseAntiforgery
9. Map* (endpoints)
10. MapFallbackToFile (SPA fallback, LAST)

Critical: Middleware order is pipeline execution order.
UseBlazorFrameworkFiles must run BEFORE routing to intercept WASM requests.

This fixes:
✓ 500 InvalidOperationException
✓ Admin login page WASM loading
✓ All static WASM files (_framework/)
✓ Portal login page
✓ Razor Pages (Sitemap, RSS)

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

src/TaxBaik.Web/Program.cs

@@ -364,13 +364,18 @@ catch (Exception ex)
 
 app.UsePathBase("/taxbaik");
 app.UseResponseCompression();
+
+// WASM 프레임워크 파일 (정적 파일 전에)
+app.UseBlazorFrameworkFiles("/admin");
+app.UseBlazorFrameworkFiles("/portal");
+
+// 정적 파일 제공 (정적 경로별)
 app.UseStaticFiles();
+app.UseStaticFiles("/admin");
+app.UseStaticFiles("/portal");
+
 app.UseSession();  // TempData 쿠키 저장소
 app.UseRouting();
-app.UseRateLimiter();
-app.UseAuthentication();
-app.UseAuthorization();
-app.UseAntiforgery();
 
 if (!app.Environment.IsDevelopment())
 {
@@ -378,20 +383,19 @@ if (!app.Environment.IsDevelopment())
     app.UseHsts();
 }
 
-// Admin & Portal Blazor WebAssembly SPA 호스팅 (미들웨어 먼저!)
-app.UseBlazorFrameworkFiles("/admin");
-app.UseStaticFiles("/admin");
-app.UseBlazorFrameworkFiles("/portal");
-app.UseStaticFiles("/portal");
+app.UseRateLimiter();
+app.UseAuthentication();
+app.UseAuthorization();
+app.UseAntiforgery();
 
-// API + Razor Pages + 정적 파일 매핑 (라우팅은 나중에)
+// API + Razor Pages + 정적 자산 매핑
 app.MapControllers();
 app.MapFastEndpoints();
 app.MapHealthChecks("/healthz");
-app.MapRazorPages();  // Sitemap.cshtml이 여기서 먼저 매치됨!
+app.MapRazorPages();  // Sitemap.cshtml, Rss.cshtml, Feed.cshtml
 app.MapStaticAssets();
 
-// SPA 라우팅 폴백 (각 경로에서 index.html 제공) - 가장 마지막에!
+// SPA 라우팅 폴백 (가장 마지막에!)
 app.MapFallbackToFile("admin/{*path:nonfile}", "admin/index.html");
 app.MapFallbackToFile("portal/{*path:nonfile}", "portal/index.html");