Add device detection and PDF generation features; refactor AuthDialog and update print utilities

src/FrontOffice.Main/ConfigureServices.cs

@@ -30,9 +30,16 @@ public static class ConfigureServices
             config.JsonSerializerOptions.WriteIndented = false;
         });
 
+        // Access HttpContext for User-Agent
+        services.AddHttpContextAccessor();
+
         // Register custom services
         services.AddScoped<AuthService>();
         services.AddScoped<AuthDialogService>();
+        // Device detection: very light, dependency-free
+        services.AddScoped<IDeviceDetector, DeviceDetector>();
+        // PDF generation
+        services.AddSingleton<FrontOffice.Main.Utilities.Pdf.IHtmlToPdfService, FrontOffice.Main.Utilities.Pdf.HtmlToPdfService>();
 
         return services;
     }