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_system/params/model.py

@@ -1,25 +1,69 @@
 # -*- coding: utf-8 -*-
 
-from typing import Optional
-from sqlalchemy import String, Boolean
-from sqlalchemy.orm import Mapped, mapped_column
+from typing import TYPE_CHECKING
+from sqlalchemy import String, Boolean, Integer, ForeignKey
+from sqlalchemy.orm import relationship, Mapped, mapped_column
 
-from app.core.base_model import CreatorMixin
+from app.core.base_model import ModelMixin, UserMixin, TenantMixin
+
+if TYPE_CHECKING:
+    from app.api.v1.module_system.tenant.model import TenantModel
+    from app.api.v1.module_system.user.model import UserModel
 
 
-class ParamsModel(CreatorMixin):
+class ParamsModel(ModelMixin, UserMixin, TenantMixin):
     """
-    系统配置表
+    参数配置表
+    
+    参数配置隔离策略:
+    =============
+    - 系统级参数(tenant_id=NULL):
+      * 平台级配置参数,影响所有租户
+      * config_type=True表示系统内置,不可删除
+      * 如:系统名称、Logo、邮件配置等
+      
+    - 租户级参数(tenant_id>1):
+      * 租户自定义配置参数,仅本租户生效
+      * config_type=False表示可自定义
+      * 如:租户LOGO、业务配置等
+      
+    - 不需要customer_id:
+      * 参数是租户级配置,不属于客户
+    
+    用于存储系统配置参数，包括：
+    - 系统级别参数
+    - 租户级别参数
+    - 配置项的名称、键、值和类型等信息
     """
-    __tablename__ = "system_param"
-    __table_args__ = ({'comment': '系统参数表'})
-    __loader_options__ = ["creator"]
+    __tablename__: str = "system_param"
+    __table_args__: dict[str, str] = ({'comment': '系统参数表'})
 
-    # 基础字段
-    config_name: Mapped[str] = mapped_column(String(500), nullable=False, unique=True, comment='参数名称')
-    config_key: Mapped[str] = mapped_column(String(500), nullable=False, unique=True, comment='参数键名')
-    config_value: Mapped[Optional[str]] = mapped_column(String(500), comment='参数键值')
+    # 覆盖TenantMixin的tenant_id为可选(支持系统级参数)
+    tenant_id: Mapped[int | None] = mapped_column(  # type: ignore
+        Integer,
+        ForeignKey("system_tenant.id", ondelete="CASCADE"),
+        default=None,
+        nullable=True,
+        index=True,
+        comment="所属租户ID(NULL表示系统级参数,所有租户共享)"
+    )
+
+    config_name: Mapped[str] = mapped_column(String(500), nullable=False, comment='参数名称')
+    config_key: Mapped[str] = mapped_column(String(500), nullable=False, comment='参数键名')
+    config_value: Mapped[str | None] = mapped_column(String(500), comment='参数键值')
     config_type: Mapped[bool] = mapped_column(Boolean, default=False, nullable=True, comment="系统内置(True:是 False:否)")
-    status: Mapped[bool] = mapped_column(Boolean(), default=True, nullable=False, comment="是否启用(True:启用 False:禁用)")
-
-
+    
+    # 关联关系 (继承自UserMixin和TenantMixin)
+    tenant: Mapped["TenantModel | None"] = relationship(
+        foreign_keys="ParamsModel.tenant_id",
+        lazy="selectin"
+    )
+    created_by: Mapped["UserModel | None"] = relationship(
+        foreign_keys="ParamsModel.created_id",
+        lazy="selectin"
+    )
+    updated_by: Mapped["UserModel | None"] = relationship(
+        foreign_keys="ParamsModel.updated_id",
+        lazy="selectin"
+    )
+