feat(recommend): 추천 스냅샷 lock을 적용한다

src/main/kotlin/kr/co/vividnext/sodalive/v2/recommend/adapter/out/scheduler/RecommendationSnapshotScheduler.kt

@@ -1,15 +1,29 @@
 package kr.co.vividnext.sodalive.v2.recommend.adapter.out.scheduler
 
 import kr.co.vividnext.sodalive.v2.recommend.application.RecommendationSnapshotRefreshService
+import org.redisson.api.RedissonClient
 import org.springframework.scheduling.annotation.Scheduled
 import org.springframework.stereotype.Component
+import java.util.concurrent.TimeUnit
 
 @Component
 class RecommendationSnapshotScheduler(
-    private val refreshService: RecommendationSnapshotRefreshService
+    private val refreshService: RecommendationSnapshotRefreshService,
+    private val redissonClient: RedissonClient
 ) {
     @Scheduled(cron = "0 0 6 * * *", zone = "Asia/Seoul")
     fun refreshDailySnapshots() {
-        refreshService.refreshDailySnapshots()
+        val lockName = "lock:recommendation-snapshot-refresh"
+        val lock = redissonClient.getLock(lockName)
+
+        try {
+            if (lock.tryLock(0, -1, TimeUnit.SECONDS)) {
+                refreshService.refreshDailySnapshots()
+            }
+        } finally {
+            if (lock.isHeldByCurrentThread) {
+                lock.unlock()
+            }
+        }
     }
 }