- .gitignore: whitelist Dockerfile, docker-compose.yml, docker/ so they
are actually tracked (the * catch-all was silently dropping them)
- Dockerfile: build and ship the archivr CLI alongside archivr-server so
users can run `archivr init` inside the container on first setup
- docker/config.example.toml: fix archive_path to point at the .archivr
subdirectory that archivr init creates (not the parent directory), which
is what read_archive_paths expects
- docs/README.md: replace the bare mkdir quickstart step with
`archivr init`, explain why mkdir is insufficient; add a callout that
auth_db_path must be set explicitly to a writable path when the config
mount is read-only
