Every tile image gets ImageObject license data so search engines can list it
as Creative Commons, the build writes sitemap.xml with all tile images,
robots.txt points at it, unknown paths get a real 404 instead of the gallery,
and the page gets a descriptive title, canonical, large image previews and
an og.png collage for link previews.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
