feat(audio-recommendation): 오디오 추천 점수 정책을 추가한다

src/test/kotlin/kr/co/vividnext/sodalive/v2/audio/recommendation/domain/AudioRecommendationScorePolicyTest.kt

@@ -0,0 +1,44 @@
+package kr.co.vividnext.sodalive.v2.audio.recommendation.domain
+
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.DisplayName
+import org.junit.jupiter.api.Test
+import java.time.LocalDateTime
+
+class AudioRecommendationScorePolicyTest {
+    private val policy = AudioRecommendationScorePolicy()
+    private val now = LocalDateTime.of(2026, 6, 23, 12, 0)
+
+    @Test
+    @DisplayName("New & Hot 점수는 원본 count를 정규화하지 않고 가중합으로 계산한다")
+    fun shouldCalculateNewAndHotScoreWithoutNormalization() {
+        val score = policy.calculateNewAndHotScore(10, 4, 2, now.minusDays(2), now)
+
+        assertEquals(485.5, score)
+    }
+
+    @Test
+    @DisplayName("추천 오디오 점수는 원본 count와 최신성 배수를 가중합으로 계산한다")
+    fun shouldCalculateRecommendedAudioScoreWithoutNormalization() {
+        val score = policy.calculateRecommendedAudioScore(10, 4, 2, now.minusDays(10), now)
+
+        assertEquals(601.0, score)
+    }
+
+    @Test
+    @DisplayName("최신성 배수는 정책별 일수 경계를 적용한다")
+    fun shouldReturnRecencyMultipliersByPolicyBoundaries() {
+        assertEquals(1.3, policy.newAndHotRecencyMultiplier(now.minusDays(3), now))
+        assertEquals(1.15, policy.newAndHotRecencyMultiplier(now.minusDays(7), now))
+        assertEquals(1.0, policy.newAndHotRecencyMultiplier(now.minusDays(14), now))
+        assertEquals(0.8, policy.newAndHotRecencyMultiplier(now.minusDays(15), now))
+        assertEquals(1.3, policy.recommendedAudioRecencyMultiplier(now.minusDays(3), now))
+        assertEquals(1.15, policy.recommendedAudioRecencyMultiplier(now.minusDays(7), now))
+        assertEquals(1.1, policy.recommendedAudioRecencyMultiplier(now.minusDays(30), now))
+        assertEquals(1.0, policy.recommendedAudioRecencyMultiplier(now.minusDays(31), now))
+        assertEquals(1.3, policy.commentRecencyMultiplier(now.minusDays(3), now))
+        assertEquals(1.15, policy.commentRecencyMultiplier(now.minusDays(7), now))
+        assertEquals(1.0, policy.commentRecencyMultiplier(now.minusDays(14), now))
+        assertEquals(0.0, policy.commentRecencyMultiplier(now.minusDays(15), now))
+    }
+}