Every public marketing site now ships a real sitemap and a robots.txt that references it. No more crawler guessing.

• @astrojs/sitemap wired on each site. Build emits sitemap-index.xml + per-language sitemap-N.xml.
• hreflang alternates for ferrlabs.com (EN/FR) and ferrflow.com (EN/FR). Google now knows the language pairs.
• robots.txt with Allow: / and an explicit Sitemap: line.
• Changelog routes auto-included via the content collection. Every new entry shows up in the next deploy's sitemap.

Pairs with the noindex roll-out on private surfaces: search engines now have a precise picture of what's public and what isn't.