feat(auth): add SeaORM entities and DTOs for auth module

- 11 entity files mapping to all auth migration tables
- DTOs with validation: LoginReq, CreateUserReq, CreateRoleReq, etc.
- Response DTOs: UserResp, RoleResp, PermissionResp, OrganizationResp, etc.
- Added workspace dependencies: jsonwebtoken, argon2, validator, thiserror, utoipa

crates/erp-auth/src/entity/position.rs

@@ -0,0 +1,42 @@
+use sea_orm::entity::prelude::*;
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone, Debug, PartialEq, DeriveEntityModel, Serialize, Deserialize)]
+#[sea_orm(table_name = "positions")]
+pub struct Model {
+    #[sea_orm(primary_key, auto_increment = false)]
+    pub id: Uuid,
+    pub tenant_id: Uuid,
+    pub dept_id: Uuid,
+    pub name: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub code: Option<String>,
+    pub level: i32,
+    pub sort_order: i32,
+    pub created_at: DateTimeUtc,
+    pub updated_at: DateTimeUtc,
+    pub created_by: Uuid,
+    pub updated_by: Uuid,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub deleted_at: Option<DateTimeUtc>,
+    pub version: i32,
+}
+
+#[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
+pub enum Relation {
+    #[sea_orm(
+        belongs_to = "super::department::Entity",
+        from = "Column::DeptId",
+        to = "super::department::Column::Id",
+        on_delete = "Restrict"
+    )]
+    Department,
+}
+
+impl Related<super::department::Entity> for Entity {
+    fn to() -> RelationDef {
+        Relation::Department.def()
+    }
+}
+
+impl ActiveModelBehavior for ActiveModel {}