- The 'authenticate first' reminder was checking docker system info's
IndexServerAddress for 'gitea.04080616.xyz', but that field always
reports Docker Hub regardless of which registries you've logged into.
The reminder fired even right after a successful 'docker login' to
Gitea — pure noise. Reduced to a comment for the maintainer.
- The buildx error message now points at the actual root cause: buildx
is usually installed at the per-user ~/.docker/cli-plugins path, which
sudo doesn't see. Two fixes presented: docker group (no-sudo) or apt
install docker-buildx-plugin (sudo).