feat(home): 인기 커뮤니티 빈 스냅샷 marker를 저장한다

src/main/kotlin/kr/co/vividnext/sodalive/v2/recommendation/adapter/out/persistence/RecommendationSnapshotPersistenceAdapter.kt

@@ -84,7 +84,9 @@ class RecommendationSnapshotPersistenceAdapter(
     }
 
     private fun supportsEmptySnapshotMarker(sectionType: RecommendedSectionType): Boolean {
-        return sectionType == RecommendedSectionType.AI_CHARACTER || sectionType == RecommendedSectionType.CHEER_CREATOR
+        return sectionType == RecommendedSectionType.AI_CHARACTER ||
+            sectionType == RecommendedSectionType.CHEER_CREATOR ||
+            sectionType == RecommendedSectionType.POPULAR_COMMUNITY
     }
 
     companion object {

src/test/kotlin/kr/co/vividnext/sodalive/v2/recommendation/adapter/out/persistence/RecommendationSnapshotPersistenceAdapterTest.kt

@@ -217,6 +217,25 @@ class RecommendationSnapshotPersistenceAdapterTest @Autowired constructor(
         )
     }
 
+    @Test
+    fun shouldSavePopularCommunityEmptySnapshotMarkerWhenReplacingWithEmptySnapshots() {
+        val snapshotAt = LocalDateTime.of(2026, 5, 29, 23, 59, 59)
+
+        adapter.replaceSnapshots(RecommendedSectionType.POPULAR_COMMUNITY, snapshotAt, emptyList())
+
+        assertEquals(
+            emptyList<RecommendationSnapshotRecord>(),
+            adapter.findSnapshots(RecommendedSectionType.POPULAR_COMMUNITY, snapshotAt)
+        )
+        assertEquals(true, adapter.existsSnapshot(RecommendedSectionType.POPULAR_COMMUNITY, snapshotAt))
+        assertEquals(
+            listOf(0L),
+            repository.findAll()
+                .filter { it.sectionType == RecommendedSectionType.POPULAR_COMMUNITY }
+                .map { it.targetId }
+        )
+    }
+
     @Test
     fun shouldReplaceCheerCreatorEmptyMarkerWithRealSnapshots() {
         val snapshotAt = LocalDateTime.of(2026, 5, 29, 23, 59, 59)
@@ -245,6 +264,34 @@ class RecommendationSnapshotPersistenceAdapterTest @Autowired constructor(
         )
     }
 
+    @Test
+    fun shouldReplacePopularCommunityEmptyMarkerWithRealSnapshots() {
+        val snapshotAt = LocalDateTime.of(2026, 5, 29, 23, 59, 59)
+        adapter.replaceSnapshots(RecommendedSectionType.POPULAR_COMMUNITY, snapshotAt, emptyList())
+
+        adapter.replaceSnapshots(
+            RecommendedSectionType.POPULAR_COMMUNITY,
+            snapshotAt,
+            listOf(
+                RecommendationSnapshotRecord(
+                    sectionType = RecommendedSectionType.POPULAR_COMMUNITY,
+                    targetId = 19L,
+                    score = 190.0,
+                    snapshotAt = snapshotAt,
+                    randomTieBreaker = 0.9
+                )
+            )
+        )
+
+        assertEquals(listOf(19L), adapter.findSnapshots(RecommendedSectionType.POPULAR_COMMUNITY, snapshotAt).map { it.targetId })
+        assertEquals(
+            listOf(19L),
+            repository.findAll()
+                .filter { it.sectionType == RecommendedSectionType.POPULAR_COMMUNITY }
+                .map { it.targetId }
+        )
+    }
+
     private fun snapshot(
         sectionType: RecommendedSectionType,
         targetId: Long,