Abilities API Implement — WooCommerce extension playbook

This skill drives a WooCommerce extension from "no abilities registered" to "draft PR open, ability surface verified" in one pass. It consumes an audit doc produced upstream by wp-abilities-audit and walks through the phases: scaffold the registrar, land one commit per ability, run the integration harness, open the PR.

Hard handoff — this skill requires a valid audit doc and exits with an error if one cannot be found or parsed.