fix(reservation): Reservation 엔티티 정규화 및 save 메서드 리팩터링

- Reservation 엔티티에서 name 필드 제거 (Member 연관관계로 대체)
- Reservation 생성자를 Member 기반으로 통일하여 일관성 확보
- save 메서드에서 Reservation 생성 시 불필요한 if-else 분기 제거
- 요청에 name이 있는 경우와 없는 경우 모두 Member를 조회한 뒤, Member를 기반으로 예약 생성
- 정규화 원칙 준수 및 예약 생성 로직 안정성 향

Author: seulnan

src/main/java/com/yourssu/roomescape/reservation/Reservation.java

@@ -16,7 +16,6 @@ public class Reservation {
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
 
-    private String name;
     private String date;
 
     @ManyToOne(fetch = FetchType.LAZY)
@@ -28,16 +27,8 @@ public class Reservation {
     @ManyToOne(fetch = FetchType.LAZY)
     private Theme theme;
 
-    public Reservation(String name, String date, Time time, Theme theme) {
-        this.name = name;
-        this.date = date;
-        this.time = time;
-        this.theme = theme;
-    }
-
     public Reservation(Member member, String date, Time time, Theme theme) {
         this.member = member;
-        this.name = member.getName();
         this.date = date;
         this.time = time;
         this.theme = theme;

src/main/java/com/yourssu/roomescape/reservation/ReservationResponse.java

@@ -15,7 +15,7 @@ public class ReservationResponse {
     public static ReservationResponse of(Reservation reservation) {
         return new ReservationResponse(
                 reservation.getId(),
-                reservation.getName(),
+                reservation.getMember().getName(),
                 reservation.getDate(),
                 reservation.getTime().getTimeValue(),
                 reservation.getTheme().getName()

src/main/java/com/yourssu/roomescape/reservation/ReservationService.java

@@ -50,17 +50,12 @@ public ReservationResponse save(ReservationRequest request, LoginMember loginMem
                 : memberRepository.findByEmail(loginMember.getEmail())
                 .orElseThrow(() -> new MemberNotFoundException("이메일이 일치하는 회원이 없습니다."));
 
-
         Time time = timeRepository.findById(request.getTime()).orElseThrow();
         Theme theme = themeRepository.findById(request.getTheme()).orElseThrow();
 
-        Reservation reservation;
-        if (request.getName() != null && !request.getName().isBlank()) {
-            reservation = new Reservation(request.getName(), request.getDate(), time, theme);
-        } else {
-            reservation = new Reservation(member, request.getDate(), time, theme);
-        }
+        Reservation reservation = new Reservation(member, request.getDate(), time, theme);
         reservationRepository.save(reservation);
+
         return ReservationResponse.of(reservation);
     }
 
@@ -72,7 +67,7 @@ public List<ReservationResponse> findAll() {
         return reservationRepository.findAll().stream()
                 .map(it -> new ReservationResponse(
                         it.getId(),
-                        it.getName(),
+                        it.getMember().getName(),
                         it.getTheme().getName(),
                         it.getDate(),
                         it.getTime().getTimeValue()