feat: 지원 대학 단건 조회 API 추가 (#817)

어드민 지원 대학 관리에서 수정 모달을 열 때 목록 조회(search/text)
응답만 사용하고 있어 정원 외 필드가 채워지지 않는 문제가 있었다.
search/text가 반환하는 미리보기 응답에는 애초에 해당 필드들이
포함되어 있지 않아 프론트에서 해결할 수 없었다.

GET /admin/univ-apply-infos/{id}를 추가해 전체 필드를 담은
AdminUnivApplyInfoResponse를 단건으로 조회할 수 있게 했다.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EwpgqdNTrn8dGDr7g7WnYg

Author: whqtker

src/main/java/com/example/solidconnection/admin/university/controller/AdminUnivApplyInfoController.java

@@ -38,6 +38,13 @@ public ResponseEntity<UnivApplyInfoImportResponse> importUnivApplyInfos(
         return ResponseEntity.ok(adminUnivApplyInfoService.importUnivApplyInfos(request));
     }
 
+    @GetMapping("/{id}")
+    public ResponseEntity<AdminUnivApplyInfoResponse> getUnivApplyInfo(
+            @PathVariable long id
+    ) {
+        return ResponseEntity.ok(adminUnivApplyInfoService.getUnivApplyInfo(id));
+    }
+
     @PostMapping
     public ResponseEntity<AdminUnivApplyInfoResponse> createUnivApplyInfo(
             @Valid @RequestBody AdminUnivApplyInfoCreateRequest request

src/main/java/com/example/solidconnection/admin/university/service/AdminUnivApplyInfoService.java

@@ -141,6 +141,13 @@ private HostUniversity findHostUniversity(Long hostUniversityId) {
                 .orElseThrow(() -> new CustomException(UNIVERSITY_NOT_FOUND));
     }
 
+    @Transactional(readOnly = true)
+    public AdminUnivApplyInfoResponse getUnivApplyInfo(long id) {
+        UnivApplyInfo univApplyInfo = univApplyInfoRepository.findById(id)
+                .orElseThrow(() -> new CustomException(UNIV_APPLY_INFO_NOT_FOUND));
+        return AdminUnivApplyInfoResponse.from(univApplyInfo);
+    }
+
     @Transactional
     @DefaultCacheOut(
             key = {"univApplyInfoTextSearch", "university:recommend:general"},

src/test/java/com/example/solidconnection/admin/university/service/AdminUnivApplyInfoServiceTest.java

@@ -515,6 +515,43 @@ class 지원_정보_생성 {
         }
     }
 
+    @Nested
+    class 지원_정보_단건_조회 {
+
+        @Test
+        void 존재하는_id로_조회하면_상세_정보를_반환한다() {
+            // given
+            UnivApplyInfo univApplyInfo = univApplyInfoFixtureBuilder.univApplyInfo()
+                    .termId(term.getId()).koreanName("괌대학(A형)")
+                    .university(hostUniversity).homeUniversity(homeUniversity).create();
+
+            // when
+            AdminUnivApplyInfoResponse response = adminUnivApplyInfoService.getUnivApplyInfo(univApplyInfo.getId());
+
+            // then
+            assertAll(
+                    () -> assertThat(response.id()).isEqualTo(univApplyInfo.getId()),
+                    () -> assertThat(response.termId()).isEqualTo(term.getId()),
+                    () -> assertThat(response.homeUniversityId()).isEqualTo(homeUniversity.getId()),
+                    () -> assertThat(response.hostUniversityId()).isEqualTo(hostUniversity.getId()),
+                    () -> assertThat(response.studentCapacity()).isEqualTo(univApplyInfo.getStudentCapacity()),
+                    () -> assertThat(response.semesterRequirement()).isEqualTo(univApplyInfo.getSemesterRequirement()),
+                    () -> assertThat(response.detailsForLanguage()).isEqualTo(univApplyInfo.getDetailsForLanguage()),
+                    () -> assertThat(response.gpaRequirement()).isEqualTo(univApplyInfo.getGpaRequirement()),
+                    () -> assertThat(response.gpaRequirementCriteria()).isEqualTo(univApplyInfo.getGpaRequirementCriteria()),
+                    () -> assertThat(response.detailsForAccommodation()).isEqualTo(univApplyInfo.getDetailsForAccommodation())
+            );
+        }
+
+        @Test
+        void 존재하지_않는_id로_조회하면_예외가_발생한다() {
+            // when & then
+            assertThatCode(() -> adminUnivApplyInfoService.getUnivApplyInfo(invalidId))
+                    .isInstanceOf(CustomException.class)
+                    .hasMessage(ErrorCode.UNIV_APPLY_INFO_NOT_FOUND.getMessage());
+        }
+    }
+
     @Nested
     class 지원_정보_수정 {