- Split the config into a createConfig(target) factory plus a thin .cn
wrapper, so the two deployments differ in one place. The .cn build
points canonical, hreflang, og:url, sitemap and robots at that origin,
and omits social links that are not reachable from mainland China.
- Generate sitemap.xml and robots.txt per target. robots.txt is written
at build time because one static file cannot carry the right origin for
both domains.
- Emit per-page canonical, hreflang and Open Graph tags. og:title and
friends are left to the theme, which already emits them and does not
de-duplicate against site-level head entries.
- Redirect the retired /projects/ paths on Vercel, before the CN redirect
so those visitors get a single hop.
