（ hyn/multi-tenant （ ★ 2296 ）の後継 ）
https://packagist.org/packages/tenancy/tenancy
https://hpscript.com/blog/laravel-8-45-1-マルチテナントアーキテクチャ/
https://packagist.org/packages/stancl/tenancy
✔️ No model traits to change database connection
✔️ No replacing of Laravel classes (Cache, Storage, ...) with tenancy-aware classes
✔️ Built-in tenant identification based on hostname (including second level domains)