replaceRootSeo() swaps the static #root-seo fallback for the page's SSR
body by string search. The old regex required a <script> right after the
block, but Vite hoists the module script into <head> in the built
index.html, so it never matched: every prerendered page (landings, /v3,
/about, all 171 example pages) shipped the HOMEPAGE's fallback body —
same <h1>, same nav — under its own <head>. Two hundred near-duplicate
bodies, and none of the landings' actual content (h1, sections, FAQ)
ever reached the crawler.
ExamplesGallery passes a server snapshot to useSyncExternalStore so
/examples SSRs instead of falling back to meta-only.