[Feat] 질문 상태 완료 전환 API 구현

backend/src/main/java/com/example/Piroin/project/domain/question/controller/QuestionController.java

@@ -81,8 +81,8 @@ public ResponseEntity<ApiResponse<QuestionResDTO.UpdateDeleteRes>> updateQuestio
             @RequestBody QuestionReqDTO.UpdateReq request,
             @AuthenticationPrincipal Long userId
     ) {
-    return ResponseUtil.success(QuestionSuccessCode.QUESTION_UPDATED,
-            questionService.updateQuestion(questionId, request, userId));
+        return ResponseUtil.success(QuestionSuccessCode.QUESTION_UPDATED,
+                questionService.updateQuestion(questionId, request, userId));
     }
 
     // 질문 삭제
@@ -92,8 +92,19 @@ public ResponseEntity<ApiResponse<QuestionResDTO.UpdateDeleteRes>> deleteQuestio
             @PathVariable Long questionId,
             @AuthenticationPrincipal Long userId
     ) {
-    return ResponseUtil.success(QuestionSuccessCode.QUESTION_DELETED,
-            questionService.deleteQuestion(questionId, userId));
+        return ResponseUtil.success(QuestionSuccessCode.QUESTION_DELETED,
+                questionService.deleteQuestion(questionId, userId));
+    }
+
+    // 질문 상태 완료 전환 (관리자 전용)
+    // PATCH /api/questions/{questionId}/status
+    @PatchMapping("/api/questions/{questionId}/status")
+    public ResponseEntity<ApiResponse<QuestionResDTO.StatusUpdateRes>> updateQuestionStatus(
+            @PathVariable Long questionId,
+            @AuthenticationPrincipal Long userId
+    ) {
+        return ResponseUtil.success(QuestionSuccessCode.QUESTION_STATUS_UPDATED,
+                questionService.updateQuestionStatus(questionId, userId));
     }
 
     // 이해도 체크 생성

backend/src/main/java/com/example/Piroin/project/domain/question/dto/QuestionResDTO.java

@@ -86,6 +86,14 @@ public record CommentResponse(
     ) {
     }
 
+    // 질문 상태 변경 응답
+    public record StatusUpdateRes(
+            Long id,
+            Boolean isResolved,
+            LocalDateTime updatedAt
+    ) {
+    }
+
     // 질문 방 전체 응답
     public record QuestionRoomResponse(
             SessionResponse session,

backend/src/main/java/com/example/Piroin/project/domain/question/entity/Question.java

@@ -79,4 +79,10 @@ public void softDelete() {
         this.deletedAt = LocalDateTime.now();
         this.updatedAt = LocalDateTime.now();
     }
+
+    // 질문 상태를 해결 완료로 변경 (관리자만 호출)
+    public void markResolved() {
+        this.isResolved = true;
+        this.updatedAt = LocalDateTime.now();
+    }
 }

backend/src/main/java/com/example/Piroin/project/domain/question/exception/code/QuestionSuccessCode.java

@@ -15,6 +15,7 @@ public enum QuestionSuccessCode implements BaseCode {
     UNDERSTANDING_RESPONSE_OK(HttpStatus.OK, "QUESTION200_4", "이해도 응답이 반영되었습니다."),
     QUESTION_UPDATED(HttpStatus.OK, "QUESTION200_5", "질문이 수정되었습니다."),
     QUESTION_DELETED(HttpStatus.OK, "QUESTION200_6", "질문이 삭제되었습니다."),
+    QUESTION_STATUS_UPDATED(HttpStatus.OK, "QUESTION200_7", "질문 상태가 변경되었습니다."),
     QUESTION_CREATED(HttpStatus.CREATED, "QUESTION201_1", "질문이 등록되었습니다."),
     COMMENT_CREATED(HttpStatus.CREATED, "QUESTION201_2", "댓글이 등록되었습니다."),
     UNDERSTANDING_CHECK_CREATED(HttpStatus.CREATED, "QUESTION201_3", "이해도 체크가 생성되었습니다.");

backend/src/main/java/com/example/Piroin/project/domain/question/service/QuestionService.java

@@ -271,6 +271,21 @@ public QuestionResDTO.UpdateDeleteRes deleteQuestion(Long questionId, Long userI
         );
     }
 
+    // 질문 상태 완료 전환
+    // PATCH /api/questions/{questionId}/status
+    @Transactional
+    public QuestionResDTO.StatusUpdateRes updateQuestionStatus(Long questionId, Long userId) {
+        User loginUser = findLoginUser(userId);
+        validateAdmin(loginUser);   // 관리자만 호출 가능
+
+        Question question = findQuestion(questionId);
+        question.markResolved();
+
+        return new QuestionResDTO.StatusUpdateRes(
+                question.getId(), question.getIsResolved(), question.getUpdatedAt()
+        );
+    }
+
     // 이해도 체크 생성
     @Transactional
     public QuestionResDTO.UnderstandingCheckCreateResponse createUnderstandingCheck(