refactor(alembic): 优化迁移脚本生成逻辑并添加模型自动发现

添加ImportUtil工具类用于自动发现SQLAlchemy模型
优化alembic迁移脚本生成逻辑，避免空变更生成
修复前端模板中的按钮标签错误
简化revision命令参数

backend/app/api/v1/module_system/dept/model.py

@@ -1,11 +1,15 @@
 # -*- coding: utf-8 -*-
 
-from typing import Optional, List
+from typing import TYPE_CHECKING, Optional, List
 from sqlalchemy import Boolean, String, Integer, ForeignKey
 from sqlalchemy.orm import relationship, Mapped, mapped_column
 
 from app.core.base_model import ModelMixin
 
+if TYPE_CHECKING:
+    from app.api.v1.module_system.role.model import RoleModel
+    from app.api.v1.module_system.user.model import UserModel
+
 class DeptModel(ModelMixin):
     """
     部门表

backend/app/api/v1/module_system/position/model.py

@@ -4,13 +4,16 @@
 定义岗位相关数据模型
 """
 
-from typing import List
+from typing import TYPE_CHECKING, List
 
 from sqlalchemy import Boolean, String, Integer
 from sqlalchemy.orm import relationship, Mapped, mapped_column
 
 from app.core.base_model import CreatorMixin
 
+if TYPE_CHECKING:
+    from app.api.v1.module_system.user.model import UserModel
+
 
 class PositionModel(CreatorMixin):
     """