Product Strategy writes and maintains its part of - the repo-root project document that captures what the project is, who it serves, how it succeeds, and where the team is investing. The file is shared with other tools and people; this skill writes only the sections names. Downstream skills read it when it exists: , , and for what work is on-strategy; for the product name and key metrics; for the primary persona. Its frontmatter keys and this skill's section headings are the contract those skills parse - keep them for every section this skill authors; a meaning an existing section already car…