The consistency test read the detail files from disk but never checked the
aggregation map, so a slug registered on disk yet missing from index.ts --
which 404s at the detail route while still appearing in the sitemap --
passed every test. Read the map with the TypeScript AST (executing it is not
possible outside a bundler, because its imports are extensionless) and pin
the registry, the map and the files on disk to each other.

Also add an npm test script, so the suite runs without knowing the glob,
drop the duplicated hostname logic in the llms.txt route in favour of the
shared helper, and correct README and docs copy that promised content the
pages do not render.