Environment variables

Container-level settings only. Everything else (indexers, Usenet servers, naming, VPN, notifications) is set in the app under Settings, not here. PUID, PGID and TZ are read by the container entrypoint, not by the app. Every variable here except those three can also be given as NAME_FILE=/path/to/file (for example /run/secrets/x with Docker secrets): the app reads the value from that file and trims the whitespace around it. If both are set, NAME wins.