feat: integrate points with lottery participation

backend/src/main/java/com/openisle/model/LotteryPost.java

@@ -26,6 +26,9 @@ public class LotteryPost extends Post {
     @Column(nullable = false)
     private int prizeCount;
 
+    @Column(nullable = false)
+    private int pointCost;
+
     @Column
     private LocalDateTime startTime;
 

backend/src/main/java/com/openisle/model/PointHistoryType.java

@@ -8,5 +8,7 @@ public enum PointHistoryType {
     INVITE,
     FEATURE,
     SYSTEM_ONLINE,
-    REDEEM
+    REDEEM,
+    LOTTERY_JOIN,
+    LOTTERY_REWARD
 }