feat: 회원 탈퇴 기능 및 포트폴리오 데모 로그인 추가 (#60)

- 회원 탈퇴: WithdrawalService로 계정·연관 데이터 일괄 삭제 (스케줄, 수강 등록, 피드백, 세션 등)
- admin/study/teach 설정에 회원 탈퇴 페이지 및 WithdrawForm 컴포넌트 추가
- 역할별(관리자/강사/학생) 원클릭 로그인 버튼(RoleLoginButtons)
- seed-demo-accounts 스크립트로 데모 계정 시드 데이터 추가

Author: junotb

api/src/main/java/org/junotb/api/auth/SessionRepository.java

@@ -20,4 +20,9 @@ public interface SessionRepository extends JpaRepository<Session, String> {
     @Modifying
     @Query("DELETE FROM Session s WHERE s.expiresAt < :now")
     long deleteByExpiresAtBefore(@Param("now") OffsetDateTime now);
+
+    /** 회원 탈퇴: 해당 사용자의 모든 세션 삭제 */
+    @Modifying
+    @Query("DELETE FROM Session s WHERE s.userId = :userId")
+    int deleteByUserId(@Param("userId") String userId);
 }

api/src/main/java/org/junotb/api/registration/RegistrationRepository.java

@@ -2,6 +2,7 @@
 
 import jakarta.persistence.LockModeType;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
 import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
 import org.springframework.data.jpa.repository.Lock;
 import org.springframework.data.jpa.repository.Query;
@@ -110,4 +111,14 @@ List<Registration> findRecentCompletedRegistrationsByStudentId(
             @Param("studentId") String studentId,
             Pageable pageable
     );
+
+    /** 학생 탈퇴: 해당 학생의 모든 수강 등록 삭제 */
+    @Modifying
+    @Query("DELETE FROM Registration r WHERE r.student.id = :userId")
+    int deleteByStudentId(@Param("userId") String userId);
+
+    /** 강사 탈퇴: 해당 강사 스케줄의 모든 수강 등록 삭제 */
+    @Modifying
+    @Query("DELETE FROM Registration r WHERE r.schedule.user.id = :userId")
+    int deleteBySchedule_UserId(@Param("userId") String userId);
 }

api/src/main/java/org/junotb/api/schedule/ScheduleRepository.java

@@ -4,6 +4,7 @@
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
+import org.springframework.data.jpa.repository.Modifying;
 import org.springframework.data.jpa.repository.Lock;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;
@@ -133,4 +134,9 @@ List<Schedule> findRecentCompletedSchedulesForTeacher(
         @Param("teacherId") String teacherId,
         Pageable pageable
     );
+
+    /** 강사 탈퇴: 해당 강사의 모든 스케줄 삭제 */
+    @Modifying
+    @Query("DELETE FROM Schedule s WHERE s.user.id = :userId")
+    int deleteByUserId(@Param("userId") String userId);
 }

api/src/main/java/org/junotb/api/schedulefeedback/ScheduleFeedbackRepository.java

@@ -1,6 +1,7 @@
 package org.junotb.api.schedulefeedback;
 
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;
 
@@ -9,4 +10,8 @@
 public interface ScheduleFeedbackRepository extends JpaRepository<ScheduleFeedback, Long> {
     @Query("SELECT sf FROM ScheduleFeedback sf JOIN FETCH sf.schedule s WHERE s.id = :scheduleId")
     Optional<ScheduleFeedback> findByScheduleId(@Param("scheduleId") Long scheduleId);
+
+    @Modifying
+    @Query("DELETE FROM ScheduleFeedback sf WHERE sf.schedule.user.id = :userId")
+    int deleteBySchedule_UserId(@Param("userId") String userId);
 }

api/src/main/java/org/junotb/api/user/TeacherTimeOffRepository.java

@@ -1,6 +1,7 @@
 package org.junotb.api.user;
 
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;
 
@@ -30,4 +31,13 @@ List<TeacherTimeOff> findOverlappingByTeacherAndRange(
             @Param("rangeStart") OffsetDateTime rangeStart,
             @Param("rangeEnd") OffsetDateTime rangeEnd
     );
+
+    /**
+     * 강사 탈퇴: 해당 강사의 모든 휴무 삭제
+     * @param teacherId 강사 ID
+     * @return 삭제된 휴무 개수
+     */
+    @Modifying
+    @Query("DELETE FROM TeacherTimeOff t WHERE t.teacher.id = :teacherId")
+    int deleteByTeacherId(@Param("teacherId") String teacherId);
 }

api/src/main/java/org/junotb/api/user/UserController.java

@@ -11,6 +11,7 @@
 import org.junotb.api.user.web.UserUpdateRequest;
 import org.springframework.data.domain.Pageable;
 import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.annotation.AuthenticationPrincipal;
 import org.springframework.web.bind.annotation.*;
 
 import java.util.Map;
@@ -25,6 +26,20 @@
 @RequiredArgsConstructor
 public class UserController {
     private final UserService userService;
+    private final WithdrawalService withdrawalService;
+
+    /**
+     * 회원 탈퇴. 본인 인증 후 회원·스케줄·수강 등록 등 모든 연관 데이터를 삭제합니다.
+     *
+     * @param userId 인증된 사용자 ID
+     * @return 204 No Content
+     */
+    @Operation(summary = "회원 탈퇴", description = "본인 계정 및 연관 데이터를 모두 삭제합니다.")
+    @PostMapping("/me/withdraw")
+    public ResponseEntity<Void> withdraw(@AuthenticationPrincipal String userId) {
+        withdrawalService.withdraw(userId);
+        return ResponseEntity.noContent().build();
+    }
 
     /**
      * 사용자 목록을 페이징하여 조회. 이름·역할·상태로 필터링 가능.

api/src/main/java/org/junotb/api/user/WithdrawalService.java

@@ -0,0 +1,78 @@
+package org.junotb.api.user;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.junotb.api.common.exception.ResourceNotFoundException;
+import org.junotb.api.schedule.ScheduleRepository;
+import org.junotb.api.schedulefeedback.ScheduleFeedbackRepository;
+import org.junotb.api.auth.SessionRepository;
+import org.junotb.api.registration.RegistrationRepository;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+/**
+ * 회원 탈퇴 서비스.
+ * 사용자와 연관된 모든 데이터(스케줄, 수강 등록, 피드백, 가용 시간, 휴무, 세션, 계정)를 삭제합니다.
+ */
+@Service
+@Transactional
+@RequiredArgsConstructor
+@Slf4j
+public class WithdrawalService {
+
+    private final UserRepository userRepository;
+    private final ScheduleFeedbackRepository scheduleFeedbackRepository;
+    private final RegistrationRepository registrationRepository;
+    private final ScheduleRepository scheduleRepository;
+    private final TeacherTimeOffRepository teacherTimeOffRepository;
+    private final TeacherAvailabilityRepository teacherAvailabilityRepository;
+    private final SessionRepository sessionRepository;
+    private final JdbcTemplate jdbcTemplate;
+
+    /**
+     * 회원 탈퇴 처리. FK 제약 순서에 맞춰 연관 데이터를 모두 삭제합니다.
+     *
+     * @param userId 탈퇴할 사용자 ID (인증된 본인)
+     * @throws ResourceNotFoundException 사용자 미존재 시
+     */
+    public void withdraw(String userId) {
+        if (!userRepository.existsById(userId)) {
+            throw new ResourceNotFoundException("User", userId);
+        }
+
+        log.info("회원 탈퇴 시작: userId={}", userId);
+
+        // 1. 수업 피드백 (스케줄 소유 시)
+        int feedbackDeleted = scheduleFeedbackRepository.deleteBySchedule_UserId(userId);
+        log.debug("schedule_feedback 삭제: {}건", feedbackDeleted);
+
+        // 2. 수강 등록 (학생으로 등록한 것 + 강사 스케줄에 등록된 것)
+        int regByStudent = registrationRepository.deleteByStudentId(userId);
+        int regBySchedule = registrationRepository.deleteBySchedule_UserId(userId);
+        log.debug("registration 삭제: student={}, schedule={}", regByStudent, regBySchedule);
+
+        // 3. 스케줄 (강사 소유)
+        int scheduleDeleted = scheduleRepository.deleteByUserId(userId);
+        log.debug("schedule 삭제: {}건", scheduleDeleted);
+
+        // 4. 강사 휴무
+        int timeOffDeleted = teacherTimeOffRepository.deleteByTeacherId(userId);
+        log.debug("teacher_time_off 삭제: {}건", timeOffDeleted);
+
+        // 5. 강사 가용 시간
+        teacherAvailabilityRepository.deleteByTeacher(userRepository.getReferenceById(userId));
+
+        // 6. 세션 (Better-Auth + Backend 공통 테이블)
+        int sessionDeleted = sessionRepository.deleteByUserId(userId);
+        log.debug("session 삭제: {}건", sessionDeleted);
+
+        // 7. 계정 (Better-Auth, password 등 - entity 없음)
+        int accountDeleted = jdbcTemplate.update("DELETE FROM account WHERE \"userId\" = ?", userId);
+        log.debug("account 삭제: {}건", accountDeleted);
+
+        // 8. 사용자
+        userRepository.deleteById(userId);
+        log.info("회원 탈퇴 완료: userId={}", userId);
+    }
+}

web/src/app/admin/settings/withdraw/page.tsx

@@ -0,0 +1,5 @@
+import WithdrawForm from "@/components/settings/WithdrawForm";
+
+export default function AdminWithdrawPage() {
+  return <WithdrawForm />;
+}

web/src/app/study/settings/withdraw/page.tsx

@@ -0,0 +1,5 @@
+import WithdrawForm from "@/components/settings/WithdrawForm";
+
+export default function StudyWithdrawPage() {
+  return <WithdrawForm />;
+}

web/src/app/teach/settings/withdraw/page.tsx

@@ -0,0 +1,5 @@
+import WithdrawForm from "@/components/settings/WithdrawForm";
+
+export default function TeachWithdrawPage() {
+  return <WithdrawForm />;
+}