fix(testing): authorize a root key so make test survives sshd hardening

The VM test SSHes into the guest as root with a password for the whole run. archsetup hardens sshd to PermitRootLogin prohibit-password and reloads it partway through the install, so every SSH after that step failed with "Permission denied" and the run aborted before any validation — make test had been silently broken since the hardening landed.

inject_root_key authorizes a throwaway root key right after the first SSH (before archsetup runs) and the ssh/scp helpers now add -i <key> via SSH_KEY_OPT. prohibit-password still allows root key auth, so the harness survives the very hardening it validates. Password stays as the fallback, so the change is additive.

0 files changed, 0 insertions, 0 deletions