Fix Search Console coverage URLs

[mister-teddy]

Summary

• Enable trailing-slash URL generation in Docusaurus so sitemap and canonical URLs match GitHub Pages' served URLs.
• Update the manually-authored latest-news blog link to use the canonical trailing-slash path.
• Replace a published docs link that pointed at a source .md path with the generated docs URL.

Why

The Search Console coverage export showed redirect and canonical-related indexing buckets. The root cause was that generated sitemap/canonical URLs omitted trailing slashes, while GitHub Pages redirects those paths to trailing-slash versions. Aligning Docusaurus output with the served URL shape removes those avoidable crawl redirects.

Validation

• cd gh-pages && pnpm build
• Checked the rebuilt sitemap has 26 URLs.
• Checked the rebuilt sitemap has 0 URLs that emit noindex.
• Checked all rebuilt sitemap URLs return HTTP 200 on the live GitHub Pages site.

Docusaurus still reports existing warnings for inline blog authors, missing truncation markers, and stale Browserslist data; those are unrelated to this fix.