feat: add user register

internal/storage/dao/user.go

@@ -10,6 +10,7 @@ type User struct {
 	BaseModel
 	Username      string `gorm:"column:username" json:"username"`
 	Phone         string `gorm:"column:phone" json:"phone"`
+	Email         string `gorm:"column:email" json:"email"`
 	Password      string `gorm:"column:password" json:"password"`
 	WechatOpenID  string `gorm:"column:wechat_open_id" json:"wechat_open_id"`
 	WechatUnionID string `gorm:"column:wechat_union_id" json:"wechat_union_id"`
@@ -51,3 +52,14 @@ func (dao *UserDao) GetByID(tx *gorm.DB, id int64) (*User, error) {
 	}
 	return &user, nil
 }
+
+func (dao *UserDao) GetByEmail(tx *gorm.DB, email string) (*User, error) {
+	var user User
+	if err := tx.Where("email = ?", email).First(&user).Error; err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, nil
+		}
+		return nil, err
+	}
+	return &user, nil
+}