Merge remote-tracking branch 'upstream/main'

# Conflicts:
#	backend/internal/service/openai_gateway_messages.go

backend/internal/service/openai_gateway_service.go

@@ -4153,9 +4153,6 @@ func (s *OpenAIGatewayService) RecordUsage(ctx context.Context, input *OpenAIRec
 	}
 
 	billingModel := forwardResultBillingModel(result.Model, result.UpstreamModel)
-	if result.BillingModel != "" {
-		billingModel = strings.TrimSpace(result.BillingModel)
-	}
 	serviceTier := ""
 	if result.ServiceTier != nil {
 		serviceTier = strings.TrimSpace(*result.ServiceTier)