SEO: robots.txt, sitemap.xml, canonical, OG/Twitter tags, JSON-LD
(ProfessionalService) on / and /folders/, plus a reused screenshot as
og-image.png. prepare-www.mjs now copies robots/sitemap/og-image into
the build. Also carries pending mobile layout tweaks (toc/prefs bar,
viewport-fit=cover) that were already staged in the working tree.
L0–L7 folders stack on scroll with aligned max depth, labeled tabs that
stay consistent when L7 joins the rail, Cal embeds, preview screenshots,
Playwright tests, and updated README.
Co-authored-by: Cursor <cursoragent@cursor.com>
