Update swap state errors

Author: jeffyanta

pkg/code/server/transaction/errors.go

@@ -73,6 +73,10 @@ func NewIntentDeniedError(message string) IntentDeniedError {
 	}
 }
 
+func NewIntentDeniedErrorf(format string, args ...any) IntentDeniedError {
+	return NewIntentDeniedError(fmt.Sprintf(format, args...))
+}
+
 func (e IntentDeniedError) Error() string {
 	return e.message
 }

pkg/code/server/transaction/intent_handler.go

@@ -2000,7 +2000,7 @@ func validateSwapFunding(ctx context.Context, data code_data.Provider, intentRec
 	isIntentReservedForSwap := swapRecord != nil
 
 	if isIntentReservedForSwap && swapRecord.State != swap.StateCreated {
-		return nil, errors.Errorf("unexpected swap state: %s", swapRecord.State)
+		return nil, NewIntentDeniedErrorf("swap state is %s", swapRecord.State)
 	}
 
 	// Intent-specific validation for swaps

pkg/code/server/transaction/swap.go

@@ -532,7 +532,7 @@ func (s *transactionServer) Swap(streamer transactionpb.Transaction_SwapServer)
 	}
 
 	if swapRecord.State != swap.StateFunded {
-		return handleSwapError(streamer, NewSwapValidationErrorf("swap state is %s", swapRecord.State))
+		return handleSwapError(streamer, NewSwapDeniedErrorf("swap state is %s", swapRecord.State))
 	}
 
 	if owner.PublicKey().ToBase58() == swapAuthority.PublicKey().ToBase58() {