GitHub stars history / star growth chart / repo popularity over time / trending tracker. Current star count plus a sampled cumulative-stars-vs-date series for any public GitHub repo. Walks 1-10 evenly-spaced pages of /stargazers using application/vnd.github.star+json so each sample carries a starred_at timestamp. Free public API, no auth (subject to GitHub's 60 req/h unauthenticated limit).