The vault role's 'Ensure standalone Vault directories exist' task creates
/etc/vault.d and /opt/vault/data with owner: root and lacks the Darwin guard
its sibling tasks have, so it fails under macOS become=false. Unlike the
bridge dir (owned by the service user, fixable via -e), this owner: root is
hardcoded and not overridable, so the role logic must change.
Since the role lives in a separate playbooks repo, reuse the existing
post-clone patch mechanism (cf. patch_playbook_user_systemd): add
patch_playbook_vault_macos() that, on Darwin only, guards the directory task,
makes vault dirs/binary OS-conditional (macOS -> ~/Library/Application
Support/vault[/data], /opt/homebrew/bin/vault; Linux unchanged), and creates
the user-owned data dir in macos.yml. Idempotent; verified against the real
role. Documents TC-MAC-013.