feat(auth): add MockUsersRepository with seed users

packages/auth/src/infrastructure/repositories/mock-users.repository.ts

@@ -0,0 +1,26 @@
+import "reflect-metadata";
+import { injectable } from "inversify";
+
+import type { IUsersRepository } from "../../application/repositories/users-repository.interface";
+import type { User } from "../../entities/user";
+
+@injectable()
+export class MockUsersRepository implements IUsersRepository {
+  private _users: User[] = [
+    { id: "1", username: "alice", passwordHash: "hashed_password_alice" },
+    { id: "2", username: "bob", passwordHash: "hashed_password_bob" },
+  ];
+
+  async getUser(id: string): Promise<User | undefined> {
+    return this._users.find((u) => u.id === id);
+  }
+
+  async getUserByUsername(username: string): Promise<User | undefined> {
+    return this._users.find((u) => u.username === username);
+  }
+
+  async createUser(input: User): Promise<User> {
+    this._users.push(input);
+    return input;
+  }
+}