feat: 태그 응답에 난이도 목록 포함

[dforce103]

작업 내용

• 태그 조회 응답(TagResponse)에 difficulties 필드를 추가
• 태그별로 연결된 문제 난이도 목록(EASY/MEDIUM/HARD)을 함께 반환하도록 서비스/레포지토리 로직 보강
• 태그 컨트롤러/서비스 테스트를 새 응답 구조에 맞게 갱신

변경 파일

• src/main/java/com/back/domain/tag/tag/dto/TagResponse.java
• src/main/java/com/back/domain/tag/tag/repository/TagRepository.java
• src/main/java/com/back/domain/tag/tag/service/TagService.java
• src/test/java/com/back/domain/tag/tag/controller/TagControllerTest.java
• src/test/java/com/back/domain/tag/tag/service/TagServiceTest.java

[github-actions]

📊 테스트 커버리지 리포트

Overall: 🟡 Line 70% | Branch 51.7%

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📦 패키지별 커버리지

패키지	Line	Branch
🟢 problem/enums	100%	N/A
🟢 global/judge	100%	100%
🟢 testcase/entity	100%	N/A
🟢 tag/entity	100%	N/A
🟢 global/jwt	100%	75%
🟢 tag/service	100%	50%
🟢 tag/controller	100%	N/A
🟢 global/security	100%	N/A
🟢 queue/service	100%	66.7%
🟢 global/aspect	100%	50%
🟢 problemtagconnect/entity	100%	N/A
🟢 languageprofile/entity	100%	N/A
🟢 reviewschedule/controller	100%	100%
🟢 global/globalExceptionHandler	100%	0%
🟢 jpa/entity	100%	N/A
🟢 profile/service	100%	62.5%
🟢 dashboard/repository	100%	50%
🟢 member/entity	100%	50%
🟢 queue/model	100%	50%
🟢 pick/service	100%	87.5%
🟢 member/service	100%	50%
🟢 global/init	100%	N/A
🟢 profile/entity	100%	50%
🟢 websocket/pubsub	100%	66.7%
🟢 battleroom/entity	100%	0%
🟢 global/enums	100%	N/A
🟢 global/rq	100%	0%
🟢 submission/entity	100%	N/A
🟢 queue/store	100%	50%
🟢 store/redis	100%	66.7%
🟢 result/event	100%	N/A
🟢 battleparticipant/entity	100%	N/A
🟢 reviewschedule/entity	100%	N/A
🟢 reviewschedule/service	100%	60%
🟢 result/service	100%	83.3%
🟢 problem/controller	100%	50%
🟢 member/controller	100%	50%
🟢 global/exception	100%	0%
🟢 battleroom/service	100%	0%
🟢 problem/entity	100%	50%
🟢 global/websocket	100%	75%
🟢 global/async	100%	N/A
🟢 submission/entity	100%	50%
🟢 problem/util	100%	100%
🟢 global/rsData	100%	50%
🟢 solve/entity	100%	N/A
🟢 dashboard/service	96.4%	50%
🟢 problem/service	91.7%	50%
🟢 global/redis	87.5%	50%
🟢 pick/repository	85.7%	50%
🟢 rating/policy	85.7%	83.3%
🟡 dashboard/controller	75%	50%
🔴 global/scheduler	33.3%	50%
🔴 submission/controller	0%	N/A
🔴 run/controller	0%	N/A
🔴 submission/service	0%	0%
🔴 submission/controller	0%	N/A
🔴 queue/controller	0%	0%
🔴 battleroom/controller	0%	N/A
🔴 submission/service	0%	N/A
🔴 judge/event	0%	N/A
🔴 run/service	0%	N/A
🔴 run/controller	0%	N/A
🔴 auth/controller	0%	0%
🔴 result/controller	0%	N/A
🔴 run/service	0%	0%
🔴 solve/repository	N/A	N/A
🔴 profile/repository	N/A	N/A
🔴 tag/repository	N/A	N/A
🔴 translation/repository	N/A	N/A
🔴 languageprofile/repository	N/A	N/A
🔴 problem/repository	N/A	N/A
🔴 member/repository	N/A	N/A
🔴 battleparticipant/repository	N/A	N/A
🔴 submission/repository	N/A	N/A
🔴 reviewschedule/repository	N/A	N/A
🔴 submission/repository	N/A	N/A
🔴 translation/entity	N/A	N/A
🔴 battleroom/repository	N/A	N/A
🔴 testcase/repository	N/A	N/A
🔴 problemtagconnect/repository	N/A	N/A

🟢 80% 이상   🟡 50~79%   🔴 50% 미만