refactor: 예약 취소 로직 수정

- 일단 await 으로 결제 취소 -> 예약 취소 순으로 진행
- 추후 개선 예정

frontend/src/pages/MyReservationPage.tsx

@@ -168,7 +168,7 @@ const ReservationDetailView: React.FC<{
             )}
             <p><strong>카드사 / 구분:</strong> {detail.issuerCode}({detail.ownerType}) / {detail.cardType}</p>
             <p><strong>카드 번호:</strong> {detail.cardNumber}</p>
-            <p><strong>할부 방식:</strong> {detail.installmentPlanMonths === 0 ? '일시불' : `${detail.installmentPlanMonths}개월`}</p>
+            <p><strong>할부:</strong> {detail.installmentPlanMonths === 0 ? '일시불' : `${detail.installmentPlanMonths}개월`}</p>
             <p><strong>승인 번호:</strong> {detail.approvalNumber}</p>
           </>
         );
@@ -310,8 +310,8 @@ const MyReservationPage: React.FC = () => {
     try {
       setIsCancelling(true);
       setDetailError(null);
+      await cancelPayment({ reservationId: selectedReservation.id, cancelReason: reason });
       await cancelReservation(selectedReservation.id, reason);
-      cancelPayment({ reservationId: selectedReservation.id, cancelReason: reason });
       alert('예약을 취소했어요. 결제 취소까지는 3-5일 정도 소요될 수 있어요.');
       handleCloseModal();
       await loadReservations(); // Refresh the list

src/main/kotlin/roomescape/reservation/business/ReservationService.kt

@@ -175,7 +175,7 @@ class ReservationService(
             canceledBy = user.id,
             cancelReason = cancelReason,
             canceledAt = LocalDateTime.now(),
-            status = CanceledReservationStatus.PROCESSING
+            status = CanceledReservationStatus.COMPLETED
         ).also {
             canceledReservationRepository.save(it)
         }

src/main/kotlin/roomescape/reservation/docs/ReservationAPI.kt

@@ -19,7 +19,7 @@ import roomescape.reservation.web.*
 interface ReservationAPI {
 
     @Public
-    @Operation(summary = "결제 대기 예약 저장", tags = ["로그인이 필요한 API"])
+    @Operation(summary = "가장 많이 예약된 테마 조회")
     @ApiResponses(ApiResponse(responseCode = "200", description = "성공", useReturnTypeSchema = true))
     fun findMostReservedThemeIds(
         @RequestParam count: Int