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/auth/auth-machine.ts

@@ -14,6 +14,7 @@ import { signIn } from "next-auth/react";
 import type { AuthProvider } from "@/lib/auth/auth_platform";
 import type { LoginStatus } from "@/models/auth/login-status";
 import { authRepository } from "@/data/repositories/auth_repository";
+import type { IAuthRepository } from "@/data/repositories/interfaces";
 import { AuthStorage } from "@/data/storage/auth/auth_storage";
 import { deviceIdentifier } from "@/utils/device_identifier";
 import { Result } from "@/utils/result";
@@ -40,11 +41,13 @@ async function readGuestId(): Promise<string | undefined> {
 // ============================================================
 // Actors（异步服务）
 // ============================================================
+// 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 authRepo: IAuthRepository = authRepository;
 
 const emailLoginActor = fromPromise<LoginStatus, { email: string; password: string }>(
   async ({ input }) => {
     const guestId = await readGuestId();
-    const result = await authRepository.emailLogin({ ...input, guestId });
+    const result = await authRepo.emailLogin({ ...input, guestId });
     if (Result.isErr(result)) throw result.error;
     return "email" as LoginStatus;
   },
@@ -56,11 +59,11 @@ const emailRegisterThenLoginActor = fromPromise<
 >(async ({ input }) => {
   const guestId = await readGuestId();
 
-  const registerResult = await authRepository.register({ ...input, guestId });
+  const registerResult = await authRepo.register({ ...input, guestId });
   if (Result.isErr(registerResult)) throw registerResult.error;
 
   // 注册后自动登录（对齐 Dart 行为）
-  const loginResult = await authRepository.emailLogin({
+  const loginResult = await authRepo.emailLogin({
     email: input.email,
     password: input.password,
     guestId,
@@ -84,7 +87,7 @@ const oauthSignInActor = fromPromise<void, AuthProvider>(async ({ input }) => {
 const syncGoogleBackendActor = fromPromise<LoginStatus, { idToken: string }>(
   async ({ input }) => {
     const guestId = await readGuestId();
-    const result = await authRepository.googleLogin({
+    const result = await authRepo.googleLogin({
       idToken: input.idToken,
       guestId,
     });
@@ -98,7 +101,7 @@ const syncFacebookBackendActor = fromPromise<
   { accessToken: string }
 >(async ({ input }) => {
   const guestId = await readGuestId();
-  const result = await authRepository.facebookLogin({
+  const result = await authRepo.facebookLogin({
     accessToken: input.accessToken,
     guestId,
   });