Each folder gets a .env.example listing every homeserver, admin panel
and web client setting with its default (empty means the default).
Compose reads .env for ports, registry and the PostgreSQL password, and
passes it to the containers through env_file; the compose files keep
only the database driver, connection string and internal addresses.
.env is git-ignored.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>