feat(backend): 实现多租户数据隔离与权限管理架构

refactor(backend): 重构模型基类支持租户与客户隔离
feat(backend): 添加客户模块相关模型、CRUD和参数校验
docs(backend): 新增SaaS数据隔离设计方案文档
refactor(backend): 优化日志模块并添加类型注解
fix(backend): 修正字典模块查询参数移除creator字段

style(frontend): 统一按钮组件代码格式
fix(frontend): 修复表格序号计算逻辑
chore(frontend): 更新lint脚本使用pnpm替代npm

backend/app/api/v1/module_example/demo/model.py

@@ -1,19 +1,47 @@
 # -*- coding: utf-8 -*-
 
-from typing import Optional
-from sqlalchemy import Boolean, String
-from sqlalchemy.orm import Mapped, mapped_column
+from typing import TYPE_CHECKING
+from sqlalchemy import String
+from sqlalchemy.orm import Mapped, mapped_column, relationship
 
-from app.core.base_model import CreatorMixin
+from app.core.base_model import ModelMixin, UserMixin, TenantMixin, CustomerMixin
+
+if TYPE_CHECKING:
+    from app.api.v1.module_system.user.model import UserModel
+    from app.api.v1.module_system.tenant.model import TenantModel
+    from app.api.v1.module_system.customer.model import CustomerModel
 
 
-class DemoModel(CreatorMixin):
+class DemoModel(ModelMixin, UserMixin, TenantMixin, CustomerMixin):
     """
     示例表
+    
+    数据隔离策略:
+    - 租户级示例: tenant_id必填, customer_id=NULL
+    - 客户级示例: tenant_id必填, customer_id>0
+    
+    根据业务需求,此示例表支持客户级数据隔离
     """
-    __tablename__ = 'gen_demo'
-    __table_args__ = ({'comment': '示例表'})
-    __loader_options__ = ["creator"]
+    __tablename__: str = 'gen_demo'
+    __table_args__: dict[str, str] = ({'comment': '示例表'})
+    __loader_options__: list[str] = ["created_by", "updated_by", "tenant", "customer"]
 
-    name: Mapped[Optional[str]] = mapped_column(String(64), nullable=True, default='', comment='名称')
-    status: Mapped[bool] = mapped_column(Boolean(), default=True, nullable=False, comment="是否启用(True:启用 False:禁用)")
+    name: Mapped[str | None] = mapped_column(String(64), nullable=True, default='', comment='名称')
+    
+    # 关联关系 (覆盖Mixin中的property)
+    created_by: Mapped["UserModel | None"] = relationship(
+        foreign_keys="DemoModel.created_id",
+        lazy="selectin"
+    )
+    updated_by: Mapped["UserModel | None"] = relationship(
+        foreign_keys="DemoModel.updated_id",
+        lazy="selectin"
+    )
+    tenant: Mapped["TenantModel"] = relationship(
+        foreign_keys="DemoModel.tenant_id",
+        lazy="selectin"
+    )
+    customer: Mapped["CustomerModel | None"] = relationship(
+        foreign_keys="DemoModel.customer_id",
+        lazy="selectin"
+    )