fix: 콘텐츠 주문 - 포인트 결제 후 추가 결제를 해야하는 캔이 남아 있는 경우에만 캔을 결제하도록 수정 (남아 있는 캔이 없는데 결제 처리가 되서 0캔으로 데이터가 쌓이는 것 방지)

src/main/kotlin/kr/co/vividnext/sodalive/content/order/OrderService.kt

@@ -50,13 +50,20 @@ class OrderService(
         }
         order.point = usedPoint
 
-        canPaymentService.spendCan(
-            memberId = member.id!!,
-            needCan = order.can - (usedPoint / 10),
-            canUsage = CanUsage.ORDER_CONTENT,
-            order = order,
-            container = container
-        )
+        val remainingCan = order.can - (usedPoint / 10)
+        if (order.type == OrderType.RENTAL && content.isPointAvailable && usedPoint > 0) {
+            order.can = remainingCan
+        }
+
+        if (remainingCan > 0) {
+            canPaymentService.spendCan(
+                memberId = member.id!!,
+                needCan = remainingCan,
+                canUsage = CanUsage.ORDER_CONTENT,
+                order = order,
+                container = container
+            )
+        }
     }
 
     private fun orderContent(orderType: OrderType, content: AudioContent, member: Member): Order {