fix: 포인트 정책 생성 - endDate가 빈칸이면 null 처리

src/main/kotlin/kr/co/vividnext/sodalive/admin/point/CreatePointRewardPolicyRequest.kt

@@ -26,10 +26,14 @@ data class CreatePointRewardPolicyRequest(
                 .atZone(ZoneId.of("Asia/Seoul"))
                 .withZoneSameInstant(ZoneId.of("UTC"))
                 .toLocalDateTime(),
-            endDate = LocalDateTime.parse(endDate, dateTimeFormatter).withSecond(59)
+            endDate = if (endDate.isNotBlank()) {
+                LocalDateTime.parse(endDate, dateTimeFormatter).withSecond(59)
                     .atZone(ZoneId.of("Asia/Seoul"))
                     .withZoneSameInstant(ZoneId.of("UTC"))
-                .toLocalDateTime(),
+                    .toLocalDateTime()
+            } else {
+                null
+            },
             isActive = true
         )
     }