feat: setup barrelsby for automatic barrel file generation

Add barrelsby as a dev dependency with a `generate-barrels` npm script and a `barrelesby.json` config targeting `./src`. This automates creation of barrel/index files to simplify imports across the project.

src/data/models/index.ts

@@ -0,0 +1,5 @@
+// models 顶层 barrel export - 集中导出所有分类
+export * from "./auth";
+export * from "./chat";
+export * from "./metrics";
+export * from "./user";