🐛 fix: Correctly retrieve user image in GetClassUserInfo

Resolved an issue where the user's image was not being fetched correctly by joining the User table in the GetClassUserInfo method. The join ensures that all required user details, including the image, are correctly loaded and returned within the ClassMemberDTO.

Related issue: #212

repositories/class_user_repository.go

@@ -37,7 +37,7 @@ func NewClassUserRepository(db *gorm.DB) ClassUserRepository {
 // GetClassUserInfo はユーザーのクラスユーザー情報を取得します。
 func (r *classUserRepository) GetClassUserInfo(uid uint, cid uint) (dto.ClassMemberDTO, error) {
 	var classUser models.ClassUser
-	err := r.db.Where("uid = ? AND cid = ?", uid, cid).First(&classUser).Error
+	err := r.db.Joins("User").Where("class_users.uid = ? AND class_users.cid = ?", uid, cid).First(&classUser).Error
 	if err != nil {
 		if errors.Is(err, gorm.ErrRecordNotFound) {
 			return dto.ClassMemberDTO{}, errors.New(constants.UserNotFound)