feat(auth): add AuthStateService for role-based redirects

- Create Services/AuthStateService.cs with Login/Logout/GetPortalUrl
- Register as singleton in Program.cs

Co-authored-by: Velik <hongochai10@users.noreply.github.com>

apps/web-client-tpos-net/src/WebClientTpos.Client/Program.cs

@@ -20,6 +20,10 @@ builder.Services.AddSingleton(sp => new HttpClient { BaseAddress = new Uri(new U
 // VI: Thêm POS data service cho BFF API calls
 builder.Services.AddScoped<WebClientTpos.Client.Services.PosDataService>();
 
+// EN: Add auth state service for role-based redirects
+// VI: Thêm auth state service cho điều hướng theo vai trò
+builder.Services.AddSingleton<WebClientTpos.Client.Services.AuthStateService>();
+
 // EN: Add MudBlazor services
 // VI: Thêm các services của MudBlazor
 builder.Services.AddMudServices();