feat: add employee role and block backend login

controllers/auth_controller.go

@@ -43,6 +43,10 @@ func (c *AuthController) Login(ctx *gin.Context) {
 		ErrorResponse(ctx, http.StatusUnauthorized, err.Error())
 		return
 	}
+	if user.Role == "employee" {
+		ErrorResponse(ctx, http.StatusForbidden, "员工账号无后台登录权限")
+		return
+	}
 
 	token, err := c.authService.GenerateToken(user)
 	if err != nil {