종목변경 시 캔들차트 사라지는 현상 수정

backend/src/main/java/com/goldenchart/service/LiveStrategyTimeframeService.java

@@ -8,6 +8,7 @@ import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
+import java.util.Comparator;
 import java.util.Optional;
 import java.util.Set;
 
@@ -44,9 +45,12 @@ public class LiveStrategyTimeframeService {
     @Transactional(readOnly = true)
     public String resolveCandleTypeForMarket(String market) {
         return repo.findActiveByMarket(market).stream()
+                .filter(s -> s.getCandleType() != null && !s.getCandleType().isBlank())
+                .max(Comparator.comparing(
+                        GcLiveStrategySettings::getUpdatedAt,
+                        Comparator.nullsLast(Comparator.naturalOrder())))
                 .map(GcLiveStrategySettings::getCandleType)
                 .map(LiveStrategyTimeframeService::normalize)
-                .findFirst()
                 .orElse("1m");
     }