refactor: extract magic numbers to named constants for mnd lint compliance

internal/model/access_token.go

@@ -15,6 +15,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+// Package model 定义数据模型与 GORM 实体
 package model
 
 import (
@@ -25,6 +26,12 @@ import (
 	"time"
 )
 
+const (
+	tokenByteLength = 24 // Token 随机字节长度
+	maskThreshold   = 8  // 脱敏显示阈值
+)
+
+// AccessToken 个人访问令牌实体
 type AccessToken struct {
 	ID          uint64     `json:"id" gorm:"primaryKey;autoIncrement"`
 	UserID      uint64     `json:"user_id" gorm:"index;not null"`
@@ -38,7 +45,7 @@ type AccessToken struct {
 
 // GenerateTokenString 生成加密安全的随机 Token 值
 func GenerateTokenString() (string, error) {
-	bytes := make([]byte, 24)
+	bytes := make([]byte, tokenByteLength)
 	if _, err := rand.Read(bytes); err != nil {
 		return "", err
 	}
@@ -54,7 +61,7 @@ func HashToken(token string) string {
 
 // MaskTokenString 生成脱敏显示的 Token，仅保留前缀和最后四位
 func MaskTokenString(token string) string {
-	if len(token) <= 8 {
+	if len(token) <= maskThreshold {
 		return "at_****"
 	}
 	return fmt.Sprintf("%s...%s", token[:7], token[len(token)-4:])