implemented a customizable chat background system with support for patterns, solid colors, and gallery images; added a dedicated settings page with live preview and adjustable blur/dim effects, updated the image cropper to support flexible aspect ratios for wallpapers, and integrated file cleanup logic during account logout.

lib/routing/app_routes.dart

@@ -18,6 +18,7 @@ import '../view/pages/marianum_message/marianum_message_view.dart';
 import '../view/pages/more/feedback/feedback_dialog.dart';
 import '../view/pages/more/roomplan/roomplan.dart';
 import '../view/pages/more/share/qr_share_view.dart';
+import '../view/pages/settings/chat_background_settings_page.dart';
 import '../view/pages/settings/modules_settings_page.dart';
 import '../view/pages/settings/settings.dart';
 import '../view/pages/share_intent/share_chat_picker.dart';
@@ -94,6 +95,14 @@ class AppRoutes {
     pushScreen(context, withNavBar: false, screen: const ModulesSettingsPage());
   }
 
+  static void openChatBackgroundSettings(BuildContext context) {
+    pushScreen(
+      context,
+      withNavBar: false,
+      screen: const ChatBackgroundSettingsPage(),
+    );
+  }
+
   static void openFeedback(BuildContext context) {
     pushScreen(context, withNavBar: false, screen: const FeedbackDialog());
   }