A post's document link tag comes from the atUri in its frontmatter, and publish.sh writes that back only after the deploy that put the page online. Between publishing and the next commit, a built page has no tag. The deploy now runs `sequoia inject` after the build and before the upload, so the tag is restored from sequoia's own state. Inject leaves alone a tag the build already emitted and touches no page that is not a published post, so the frontmatter stays the committed source and this is only the second chance at it. The state file is gitignored: a checkout that never published finds nothing to do.