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

Cargo.toml

@@ -17,6 +17,7 @@ members = [
     "crates/erp-plugin-itops",
     "crates/erp-health",
     "crates/erp-ai",
+    "crates/erp-points",
     "crates/erp-plugin-assessment",
     "crates/erp-dialysis",
 ]
@@ -105,6 +106,7 @@ erp-config = { path = "crates/erp-config" }
 erp-plugin = { path = "crates/erp-plugin" }
 erp-health = { path = "crates/erp-health" }
 erp-ai = { path = "crates/erp-ai" }
+erp-points = { path = "crates/erp-points" }
 
 # Async streaming
 futures = "0.3"