Repo health check

We're Lumen Commerce, a small team building cross-border e-commerce SaaS, and we want to check the health of open-source dependencies before we adopt them. Build a repository health check page for github.com/vercel/next.js: at the top, a repo card and a 0–100 health score split into activity, maintainer response, contributor diversity and release rhythm, with the scoring method explained on the page. Below that: a 52-week contribution calendar, weekly commit trend, a weekday × hour commit heatmap, top contributors with the bus factor, a release timeline, issue / PR response and close times, and recent commits. Help me judge whether it's actively maintained and whether contributions are too concentrated. Style: graph-paper engineering notebook, hand-drawn charts, highlighter accents, looking good on both phones and large screens.