And every server can now back itself up, nightly

One line in config.json turns it on: "flNightlyBackup": true. Every night the server writes its whole database -- users, posts, likes, files, media -- to one dated JSON file in data/backups/, using the same export format that carried both public servers through the SQLite migration, restorable onto a fresh server with the import verb. Nothing to install, no cron, no scripts: the server does it itself, the way it should be. It's off by default; flip the flag and restart.