feat(recommend): 홈 추천 점수 정책을 추가한다

src/main/kotlin/kr/co/vividnext/sodalive/v2/recommend/domain/RecommendationScorePolicy.kt

@@ -0,0 +1,72 @@
+package kr.co.vividnext.sodalive.v2.recommend.domain
+
+import java.time.LocalDateTime
+import java.time.temporal.ChronoUnit
+
+class RecommendationScorePolicy {
+    fun calculateCreatorNewBoost(debutAt: LocalDateTime, now: LocalDateTime): Double {
+        return calculateNewBoost(debutAt, now)
+    }
+
+    fun calculateAiCharacterNewBoost(createdAt: LocalDateTime, now: LocalDateTime): Double {
+        return calculateNewBoost(createdAt, now)
+    }
+
+    fun calculateDebutCreatorScore(
+        followIncrease: Long,
+        contentActivityScore: Long,
+        communicationScore: Long,
+        newBoost: Double
+    ): Double {
+        return ((followIncrease * 0.35) + (contentActivityScore * 0.3) + (communicationScore * 0.2)) * newBoost
+    }
+
+    fun calculateAiChatScore(
+        recentChatCount: Long,
+        recentActiveUserCount: Long,
+        followIncrease: Long,
+        newBoost: Double
+    ): Double {
+        return ((0.45 * recentChatCount) + (0.35 * recentActiveUserCount) + (0.20 * followIncrease)) * newBoost
+    }
+
+    fun calculateCheerScore(
+        donationAmount: Long,
+        fanTalkCount: Long,
+        donationCount: Long,
+        newBoost: Double
+    ): Double {
+        return ((0.6 * donationAmount) + (0.3 * fanTalkCount) + (0.1 * donationCount)) * newBoost
+    }
+
+    fun calculateCommunityScore(
+        likeCount: Long,
+        commentCount: Long,
+        followerCount: Long,
+        newBoost: Double
+    ): Double {
+        return ((0.5 * likeCount) + (0.5 * commentCount) + (0.1 * followerCount)) * newBoost
+    }
+
+    fun calculateFirstAudioRecencyScore(releaseDate: LocalDateTime, now: LocalDateTime): Int {
+        val days = ChronoUnit.DAYS.between(releaseDate.toLocalDate(), now.toLocalDate())
+        return when {
+            days <= 3 -> 100
+            days <= 7 -> 80
+            days <= 14 -> 60
+            days <= 21 -> 40
+            days <= 30 -> 20
+            else -> 0
+        }
+    }
+
+    private fun calculateNewBoost(baseAt: LocalDateTime, now: LocalDateTime): Double {
+        val days = ChronoUnit.DAYS.between(baseAt.toLocalDate(), now.toLocalDate())
+        return when {
+            days <= 10 -> 1.5
+            days <= 20 -> 1.3
+            days <= 30 -> 1.2
+            else -> 1.0
+        }
+    }
+}