refactor(data): add I*Repository interfaces and depend on them in stores

为 /src/data/repositories/ 下每个仓库类增加对应的接口契约，
接口文件存放在独立的 interfaces/ 子目录中。

改动:
- 新建 4 个接口文件 (iauth_repository / ichat_repository /
  imetrics_repository / iuser_repository)，纯 type-only，方法签名
  与实现类完全一致
- 4 个实现类加 implements I{Name}Repository 子句，编译器自动校验契约
- 3 个 stores 文件 (auth / chat / user state machines) 改为依赖接口
  类型：通过 `const xxxRepo: I{Name}Repository = xxxRepository` 局部别名，
  actor 内部调用全部走别名
- barrelsby.json 加入 interfaces/ 目录，让自动 barrel 能覆盖
- Auto-regenerated repositories/index.ts 与 interfaces/index.ts

参照 storage 层已有的 IAuthStorage / IChatStorage / IUserStorage 模式。

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/stores/user/user-machine.ts

@@ -14,6 +14,10 @@ import { setup, fromPromise, assign } from "xstate";
 import type { UserView } from "@/models/user/user";
 import { userRepository } from "@/data/repositories/user_repository";
 import { authRepository } from "@/data/repositories/auth_repository";
+import type {
+  IAuthRepository,
+  IUserRepository,
+} from "@/data/repositories/interfaces";
 import { UserStorage } from "@/data/storage/user/user_storage";
 import { Result } from "@/utils/result";
 
@@ -81,10 +85,14 @@ async function readInitData(): Promise<InitData> {
 // ============================================================
 // Actors
 // ============================================================
+// 仓库以接口类型注入：调用面只看接口，运行时仍是同一单例
+const userRepo: IUserRepository = userRepository;
+const authRepo: IAuthRepository = authRepository;
+
 const userInitActor = fromPromise<InitData>(async () => readInitData());
 
 const userFetchActor = fromPromise<UserView | null>(async () => {
-  const result = await userRepository.getCurrentUser();
+  const result = await userRepo.getCurrentUser();
   if (Result.isErr(result)) return null;
   const view = toView(result.data.toJson());
   // 持久化到本地
@@ -93,7 +101,7 @@ const userFetchActor = fromPromise<UserView | null>(async () => {
 });
 
 const userLogoutActor = fromPromise<void>(async () => {
-  await authRepository.logout();
+  await authRepo.logout();
   await userStorage.clearUserData();
 });