chore: added defaul object to cost property

backend/app/services/report_service.py

@@ -373,7 +373,11 @@ class TranscriptionReportService:
                 "pagination": mongo_data,
                 "data": [],
                 "cost": {
-                     
+                    'company_id': self.company_id,
+                    'start_date': self.start_date,
+                    'end_date': self.end_date,
+                    'total_cost_hit': 0,
+                    'total_client_cost': 0
                 }  
             }