10,000-item virtualised list

Teaches: Only ~30 items are in the DOM at any time, virtualised on scroll. Scraping the visible DOM misses the rest.

Expected output: Either scroll the full list capturing items as they appear, or call the data source directly.

Submit your scraper's JSON output to /challenges/dynamic/heavy-dom/10k-items/grade (grader endpoint is part of a later phase; URL is reserved now).