Contract Product Transaction Fee duplicate handling

[StuartFerguson]

26/08/2025 08:43:54.9175 | Error |Correlation ID: 9b366b61-d396-4879-8adb-8ecbff5d7195| Shared.EventStore.SubscriptionWorker.PersistentSubscription.EventAppeared | Failed to process the event type TransactionFeeForProductAddedToContractEvent {"contractId":"f8d1516e-04b8-4467-9f41-6ef4c3fa6a05","estateId":"435613ac-a468-47a3-ac4f-649d89764c22","productId":"7618535e-c35e-4fb4-90ea-d464ec9bfd88","transactionFeeId":"d5f35e52-5179-43a7-b8cc-0a7079256d4a","description":"Merchant Commission","value":0.3} Result was One or more event handlers have failed. Error Messages [Unique constraint violation
Cannot insert duplicate key row in object 'dbo.contractproducttransactionfee' with unique index 'IX_contractproducttransactionfee_ContractProductTransactionFeeId_ContractProductId'. The duplicate key value is (d5f35e52-5179-43a7-b8cc-0a7079256d4a, 7618535e-c35e-4fb4-90ea-d464ec9bfd88).] | System.Exception