export interface UserService
  readonly version: string
  getUser(id)
  createUser(data)
export type UserId
export type UserRole
export enum Status
export class UserRepository
  constructor(private db)
  async findById(id) → Promise<User | null>
  async save(user) → Promise<void>
  static create(db) → UserRepository
class InternalHelper
  process(data) → string
export async function hashPassword(password) → Promise<string>
export const useAuth = (loginId, password) => → { user, isAuthenticated, login, logout }
