Watch
Tell it a site and run it whenever you like. Each run crawls again, compares every page with the run before — by content hash, then section by section — and records what changed with the section heading and the page. Navigation, footers, comments, timestamps and visitor counters are left out, so a bumped “last updated” line is not news. Every watch has a feed.
Nothing here runs on a schedule by itself. webgraph watch run <id> or POST /api/watch/{id}/run is what a cron entry or a GitHub Action calls; the repository ships an example workflow.