[transitrix]

Closes what's left of THQ-254 (epic THQ-243, slice 3 of 4) — most of this slice landed already in PR #57.

What this repository carries after this change

Only llms.txt changes: one new line declaring the library the same way every other page there is declared.

Status against the task's four deliverables, checked before touching anything

• Reachable from the site's own navigation — already true. There is no shared header/footer section list anywhere on this site (checked across the home page and every subpage: header/footer carry only the logo, theme toggle and language switch, never section links). Every other section is made reachable the same way the library is — a link from the home page body — and that link already shipped in PR site: serve the library index and the ArchiMate cheat sheet's page #57. Nothing to add.
• sitemap.xml regenerated and matching scripts/generate_sitemap.py — already true, verified by running the script and diffing; library/ and library/archimate-cheat-sheet/ are present with no hreflang alternate, correctly, since no de/library/ mirror exists.
• llms.txt and robots.txt updated where they enumerate sections — llms.txt did not mention the library; added one line under "Docs". robots.txt does not enumerate sections at all (just Allow: /, the /install/go/ note, and the sitemap pointer), so there is nothing there to update.
• Per-page OG metadata — already true, verified by running the og-declarations.yml check logic locally against every sitemap page: 0 errors, including both library pages.

Verification

• python scripts/generate_sitemap.py output byte-matches the committed sitemap.xml.
• Ran the indexing-declarations.yml and og-declarations.yml check logic locally against the full page set: both pass, 0 errors.
• From the site's front page a reader reaches the library without knowing its URL (via the existing "Free reference material" section).
• No hreflang alternate is emitted for any library/ page.