refactor(app): update AppBloc to handle user roles list

This refactors the AppBloc's user change handler to correctly evaluate dashboard access based on the user.roles list instead of a singular role property.

The logic now checks for 'admin' or 'publisher' roles to grant authenticated status. It also corrects the condition for fetching user settings to depend on this authenticated status, not just the presence of a user object.

Author: fulleni

lib/app_configuration/view/app_configuration_page.dart

@@ -282,12 +282,7 @@ class _AppConfigurationPageState extends State<AppConfigurationPage> {
             horizontal: AppSpacing.xxl,
           ),
           children: [
-            _UserPreferenceLimitsForm(refactor(app_configuration): use UserRoles string constants
-            
-            This change refactors the AppConfigurationPage and its helper form widgets to use string-based role constants from the `UserRoles` class instead of an obsolete `UserRole` enum.
-            
-            This aligns the UI with the updated `User` model, which represents roles as a list of strings, ensuring consistency across the application.
-            
+            _UserPreferenceLimitsForm(
               userRole: UserRoles.guestUser,
               appConfig: appConfig,
               onConfigChanged: (newConfig) {