🐛 Refactor: Update printer status handling and session management. Improved caching mechanism for live printer status and added summary functionality. Removed obsolete database files for better organization.

backend/blueprints/guest.py

@@ -588,7 +588,7 @@ def api_get_notifications():
         with get_cached_session() as db_session:
             query = db_session.query(Notification).filter_by(
                 user_id=current_user.id,
-                read=False
+                is_read=False
             )
             
             if since_date:
@@ -619,7 +619,7 @@ def api_mark_notification_read(notification_id):
             if not notification:
                 return jsonify({"error": "Benachrichtigung nicht gefunden"}), 404
             
-            notification.read = True
+            notification.is_read = True
             db_session.commit()
             
             return jsonify({"success": True})