Update MudBlazor integration, improve captcha handling, and upgrade project dependencies

src/FrontOffice.Main/Program.cs

@@ -23,7 +23,14 @@ ValidatorOptions.Global.LanguageManager = new CustomFluentValidationLanguageMana
 
 #endregion
 var appSettings = builder.Configuration.Get<AppSettings>();
-UrlUtility.DownloadUrl = appSettings.DownloadUrl;
+if (!string.IsNullOrWhiteSpace(appSettings?.DownloadUrl))
+{
+    UrlUtility.DownloadUrl = appSettings.DownloadUrl;
+}
+else
+{
+    UrlUtility.DownloadUrl = string.Empty; // fallback to empty
+}
 
 builder.Services.Configure<EncryptionSettings>(builder.Configuration.GetSection("EncryptionSettings"));
 builder.Services.AddSingleton<MobileNumberEncryptor>();
@@ -52,10 +59,10 @@ app.Run();
 
 public class AppSettings
 {
-    public string DownloadUrl { get; set; }
+    public required string DownloadUrl { get; set; }
 }
 public class EncryptionSettings
 {
-    public string Key { get; set; }
-    public string IV { get; set; }
+    public required string Key { get; set; }
+    public required string IV { get; set; }
 }