feat(types): add userByName method to tailor.idp.Client

[k1LoW]

Summary

Add userByName(name: string): Promise<User> method to tailor.idp.Client type definitions, enabling user lookup by name.

Added Client method

• userByName(name) - Get a user by name

Usage

const client = new tailor.idp.Client({ namespace: 'my-namespace' });

// Existing: get user by ID
const user = await client.user('user-uuid');

// New: get user by name
const user = await client.userByName('foo@example.com');

[toiroakr]

👍