feat(session): 제목 미입력 시 모드+직군 규칙 제목 자동 생성

히스토리에서 "면접 #id" 대신 의미 있는 제목을 보이도록, 세션 생성 시
제목이 비어 있으면 "{직군} {모드}"(예: "백엔드 기술 면접")로 채운다.
SessionMode/JobCategory 에 koreanLabel() 추가.

부수: StackupApplicationTests 에 누락됐던 SessionQuestionPoolRepository
@MockitoBean 추가 (질문 풀 도입 PR에서 빠져 컨텍스트 로드가 깨져 있던 것 복구).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: i3months

backend/src/main/java/com/stackup/stackup/session/application/SessionService.java

@@ -43,9 +43,10 @@ public class SessionService {
     @Transactional
     public SessionResult create(Long userId, SessionCreateCommand command) {
         User user = loadUser(userId);
+        String title = resolveTitle(command);
         InterviewSession session = sessionRepository.save(InterviewSession.create(
             user,
-            command.title(),
+            title,
             command.memo(),
             command.mode(),
             command.jobCategory(),
@@ -145,6 +146,16 @@ public SessionResult updateMeta(Long userId, Long sessionId, String title, Strin
         return SessionResult.of(session, contextDocumentIds(sessionId));
     }
 
+    // 제목 미입력 시 모드+직군으로 규칙 기반 제목 생성 (예: "백엔드 기술 면접").
+    // 히스토리에서 "면접 #id" 대신 의미 있는 제목을 보이게 한다.
+    private String resolveTitle(SessionCreateCommand command) {
+        String title = command.title();
+        if (title != null && !title.isBlank()) {
+            return title;
+        }
+        return command.jobCategory().koreanLabel() + " " + command.mode().koreanLabel();
+    }
+
     private User loadUser(Long userId) {
         return userRepository.findByIdAndDeletedFalse(userId)
             .orElseThrow(() -> new DomainException(ApiErrorCode.USER_NOT_FOUND));

backend/src/main/java/com/stackup/stackup/session/domain/JobCategory.java

@@ -4,5 +4,14 @@ public enum JobCategory {
     FRONTEND,
     BACKEND,
     INFRA,
-    DBA
+    DBA;
+
+    public String koreanLabel() {
+        return switch (this) {
+            case FRONTEND -> "프론트엔드";
+            case BACKEND -> "백엔드";
+            case INFRA -> "인프라";
+            case DBA -> "DBA";
+        };
+    }
 }

backend/src/main/java/com/stackup/stackup/session/domain/SessionMode.java

@@ -3,5 +3,13 @@
 public enum SessionMode {
     TECHNICAL,
     PERSONALITY,
-    INTEGRATED
+    INTEGRATED;
+
+    public String koreanLabel() {
+        return switch (this) {
+            case TECHNICAL -> "기술 면접";
+            case PERSONALITY -> "인성 면접";
+            case INTEGRATED -> "종합 면접";
+        };
+    }
 }

backend/src/test/java/com/stackup/stackup/StackupApplicationTests.java

@@ -13,6 +13,7 @@
 import com.stackup.stackup.session.domain.MessageVoiceAnalysisRepository;
 import com.stackup.stackup.session.domain.SessionContextRepository;
 import com.stackup.stackup.session.domain.SessionFeedbackRepository;
+import com.stackup.stackup.session.domain.SessionQuestionPoolRepository;
 import com.stackup.stackup.user.domain.UserRepository;
 import com.stackup.stackup.user.domain.consent.UserConsentRepository;
 import org.junit.jupiter.api.Test;
@@ -61,6 +62,9 @@ class StackupApplicationTests {
 	@MockitoBean
 	private SessionFeedbackRepository sessionFeedbackRepository;
 
+	@MockitoBean
+	private SessionQuestionPoolRepository sessionQuestionPoolRepository;
+
 	@MockitoBean
 	private MessageVoiceAnalysisRepository messageVoiceAnalysisRepository;
 

backend/src/test/java/com/stackup/stackup/session/application/SessionServiceTest.java

@@ -63,6 +63,34 @@ void create_savesSessionAndPublishesEvent() {
         verify(events).publishEvent(any(SessionCreatedEvent.class));
     }
 
+    @Test
+    void create_generatesTitleFromModeAndJobWhenBlank() {
+        User user = userFixture(1L);
+        when(userRepository.findByIdAndDeletedFalse(1L)).thenReturn(Optional.of(user));
+        when(sessionRepository.save(any(InterviewSession.class))).thenAnswer(inv -> inv.getArgument(0));
+
+        SessionResult result = service.create(1L, new SessionCreateCommand(
+            "  ", null, SessionMode.TECHNICAL, JobCategory.BACKEND,
+            5, 30, null, null, List.of()
+        ));
+
+        assertThat(result.title()).isEqualTo("백엔드 기술 면접");
+    }
+
+    @Test
+    void create_keepsProvidedTitle() {
+        User user = userFixture(1L);
+        when(userRepository.findByIdAndDeletedFalse(1L)).thenReturn(Optional.of(user));
+        when(sessionRepository.save(any(InterviewSession.class))).thenAnswer(inv -> inv.getArgument(0));
+
+        SessionResult result = service.create(1L, new SessionCreateCommand(
+            "내가 정한 제목", null, SessionMode.INTEGRATED, JobCategory.FRONTEND,
+            5, 30, null, null, List.of()
+        ));
+
+        assertThat(result.title()).isEqualTo("내가 정한 제목");
+    }
+
     @Test
     void create_linksAnalyzedContextDocuments() {
         User user = userFixture(1L);