✨ feat: 그룹이름 수정 기능 추가

src/main/java/com/hatoo/domain/groups/Group.java

@@ -74,6 +74,11 @@ public void updateInviteCode(String inviteCode, LocalDateTime expiryDate) {
         this.inviteCodeExpiryDate = expiryDate;
     }
 
+    // 그룹 이름 수정
+    public void updateName(String name) {
+        this.name = name;
+    }
+
     // 방장 변경
     public void changeAssigner(UUID newAssignerId) {
         this.assignerId = newAssignerId;

src/main/java/com/hatoo/domain/groups/GroupController.java

@@ -1,6 +1,7 @@
 package com.hatoo.domain.groups;
 
 import com.hatoo.domain.groups.dto.*;
+import jakarta.validation.Valid;
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.Parameter;
 import io.swagger.v3.oas.annotations.tags.Tag;
@@ -106,6 +107,16 @@ public ResponseEntity<Boolean> profileImgSelect(
         return ResponseEntity.ok(groupService.profileImgSelectApi(authToken, request, groupId));
     }
 
+    @Operation(summary = "그룹 이름 수정", description = "방장이 그룹 이름을 수정합니다.")
+    @PatchMapping("/{groupId}/name")
+    public ResponseEntity<Boolean> updateGroupName(
+            @Parameter(hidden = true) @RequestHeader("Authorization") String accessToken,
+            @PathVariable UUID groupId,
+            @Valid @RequestBody GroupUpdateNameRequest request) {
+        String token = accessToken.startsWith("Bearer ") ? accessToken.substring(7) : accessToken;
+        return ResponseEntity.ok(groupService.updateGroupName(token, groupId, request));
+    }
+
     @Operation(summary = "그룹별 알림 설정 조회", description = "특정 그룹의 알림 설정을 조회합니다.")
     @GetMapping("/{groupId}/alarm")
     public ResponseEntity<GroupAlarmSettingResponse> getGroupAlarmSetting(

src/main/java/com/hatoo/domain/groups/GroupService.java

@@ -409,6 +409,29 @@ public GroupAlarmSettingResponse updateGroupAlarmSetting(String accessToken, UUI
         return GroupAlarmSettingResponse.from(setting);
     }
 
+    // 그룹 이름 수정
+    @Transactional
+    public boolean updateGroupName(String accessToken, UUID groupId, GroupUpdateNameRequest request) {
+
+        jwtUtil.validateToken(accessToken);
+        String loginId = jwtUtil.extractLoginId(accessToken);
+
+        User user = userRepository.findByLoginId(loginId)
+                .orElseThrow(() -> new CustomException(ErrorMessage.USER_NOT_FOUND));
+
+        Group group = groupRepository.findById(groupId)
+                .orElseThrow(() -> new CustomException(ErrorMessage.GROUP_NOT_FOUND));
+
+        // 방장 여부 검증
+        if (!user.getId().equals(group.getAssignerId())) {
+            throw new CustomException(ErrorMessage.NO_DELETE_PERMISSION);
+        }
+
+        group.updateName(request.getName());
+
+        return true;
+    }
+
     // 초대코드 생성 유틸
     private String generateInviteCode() {
         return String.format("%04d", new Random().nextInt(10000));

src/main/java/com/hatoo/domain/groups/dto/GroupUpdateNameRequest.java

@@ -0,0 +1,13 @@
+package com.hatoo.domain.groups.dto;
+
+import jakarta.validation.constraints.NotBlank;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter
+@NoArgsConstructor
+public class GroupUpdateNameRequest {
+
+    @NotBlank(message = "그룹 이름은 필수입니다.")
+    private String name;
+}