refactor: 积分系统拆分为独立 erp-points crate

- 新建 erp-points crate（8 Entity + account/product service + handler）
- 商品 CRUD 和账户管理完整实现，订单/签到/规则端点暂返回 501
- 注册到 workspace + erp-server 路由 /api/v1/points/*
- API 路径不变，前端无需修改

crates/erp-points/src/dto/mod.rs

@@ -0,0 +1,6 @@
+pub mod points_dto;
+
+#[derive(Debug, serde::Deserialize, utoipa::ToSchema)]
+pub struct DeleteWithVersion {
+    pub version: i32,
+}