Add logging for Kafka message consumption

- Include informative log message when starting Kafka message consumption
- Enhance observability of log consumer service startup process

internal/service/log_consumer.go

@@ -116,6 +116,7 @@ func NewLogConsumerService(db *gorm.DB, esStore *esStore.ESStore) *LogConsumerSe
 }
 
 func (s *LogConsumerService) Consume() {
+	log.Info().Msg("start consume kafka message")
 	for {
 		m, err := s.consumer.ReadMessage(context.Background())
 		if err != nil {