content/docs/releases/v17.mdx: @objectstack/spec 17.4.0 is published (it has a `## 17.4.0` section in packages/spec/CHANGELOG.md) but NO heading on this page names the 17.4 series. Fold it in under a running section — the shape both current pages use is "# What's new in 17.4.0" plus "### 17.4.0" in the upgrade checklist. This gate writes no prose and cannot: a curated section is a judgement about what is user-facing, read out of the per-package changelogs. It only reports that the section is absent.