Pulumi does not publish apt or yum repositories — the URLs the setup
function referenced (api.pulumi.com/releases/sdk/{apt,rpm}-keyring.gpg
and {apt,yum}.releases.pulumi.com) return 404 / do not resolve, which
broke `bootstrap_environment.py` on every fresh Linux run.
Replace `setup_pulumi_repo` with a special-package installer that
downloads the official GitHub release tarball, verifies the SHA256
against the published checksums file, extracts to /opt/pulumi, and
exposes the binaries via PATH — the same pattern used for Neovim.
macOS continues to install Pulumi via brew.
https://claude.ai/code/session_018L1gFoc8L3CYqLE2wNjpy6