Related posts were 4 text-only cards. They now carry the post's language-specific
ogImage (/og/<slug>.jpg for EN, /og/zh-<slug>.jpg for ZH), so an English page never
shows Chinese art. Grid is 3 across above 900px, 2 across below, and phones show the
first 4 only; read-time is dropped under 600px so the date fits.
Verified in the built HTML + headless Chrome at 1264/884/500px: 3/2/2 columns,
6/6/4 visible cards, no horizontal overflow, all six images decoded.
The crawler/sitemap mechanics now live in the repo doc, not just in the
commit log: robots.txt is a build-time endpoint that must stay pure ASCII
(no charset on a text/plain response means non-ASCII renders as mojibake),
the policy is allow-all with enforcement deliberately left to Cloudflare,
why writing a real robots.txt demotes Cloudflare's placeholder from
replacement to prepend, and that lastmod/hreflang are derived so they must
never be hand-authored.