No layers: a local web server is required
If you open visor.html by double-clicking, the URL starts with file:// and the browser will not load manifest.json or .geojson files (you may see “Failed to fetch”).
From your project root (where index.html lives), run in a terminal:
npx --yes serve . -l 3333
Then open: http://localhost:3333/Visor/visor.html (Live Server or any static server with the same path works too).
Click the map: polygons containing the point, nearby lines, and points within a short radius.
