Step 3 of the ordered ghp plugin add: import vault-plugin-secrets-ghp into the
OpenBao secret plugin catalog (type secret, sha256 pins the v0.1.0 binary that
puppet-prod#520 installs). config/plugins/* is generically discovered, so this is
the sole file. Catalog import uses the shared sudo-protected
sys/plugins/catalog grant; no per-engine policy needed here.
Must apply AFTER the binary is installed (puppet#520) and BEFORE the engine
resources (#121) mount+configure it.