Upgrade VM

IV VMs run the ghcr.io/kylelundstedt/exeslim-dev base (which keeps Shelley via LABEL exe.dev/install-shelley=true plus its own units) and get their tooling from provision-iv.sh in the iv-provision repo. So "upgrading" a VM is normally just re-running the provisioner at a newer commit — in place, no recreate, no disk wipe, no tailnet churn.

Full destroy/recreate is now the exception, needed only when you genuinely want a fresh disk or the exe.dev-managed base has changed in a way re-provisioning can't pick up.

Path A — Re-provision in place (default)

The user provides the VM name and a target release tag of the iv-provision repo.

One SSH command at a time — never parallel SSH.