- POST /_seo/api/v1/registry/routes (public, bucket seo-notfound): the
frontend server reports its static routes with the bearer token
golem15.seo.route_report_token, else notfound_token (constant-time;
both empty answer 404); at most 2000 paths
- unknown paths become registry pages (origin reported, kind page, a name
from the last segment), known ones get reported_at; paths another
content type owns and invalid ones are skipped; nothing is deleted or
overwritten, and the report's time marks missing pages