Simplify the release skills to start, changelog and check

.github/pull_request_template.md

@@ -10,3 +10,15 @@
 
 - [ ] For a product change: milestone set to the release and `feature` or `bugfix` label added
 - [ ] For a product change: this PR is linked from the product PR's documentation checklist
+
+### Release note corrections
+
+_Read by the release check when the release notes are written. Fix an item if it's wrong; keep the heading and one line per product PR. Delete the section if it's empty._
+
+<!-- - memgraph/memgraph#NNNN: what the product PR's release note gets wrong or misses. -->
+
+### Noticed, not fixed
+
+_Read by the release check, which fixes these in one PR per release. Fix an item if it's wrong; keep the heading and one line per item, starting with the page. Delete the section if it's empty._
+
+<!-- - `pages/<path>.mdx`: what's broken outside this PR's change, and where on the page. -->

AGENTS.md

@@ -35,9 +35,16 @@ The short version, for everyone:
 ## Branches and PRs
 
 - Docs for a product change go to the docs release branch for that release
-  (`release/<version>`); other changes go to `main`.
+  (`release/<version>`, in the docs milestone `<version>`); other changes go
+  to `main`.
+- Releases follow the skills in `skills/`: `new-release-branch` creates the
+  release branch, docs milestone and release PR; `write-changelog-item`
+  writes each release note; `check-release` finds what the release still
+  needs and, on release day, finishes it.
 - Use `.github/pull_request_template.md` and name the product PR as
   `memgraph/memgraph#NNNN`.
+- Keep the headings and line format of "Release note corrections" and
+  "Noticed, not fixed" in a docs PR description: `check-release` reads them.
 
 ## Run locally
 

scripts/check-docs.mjs

@@ -1,7 +1,8 @@
 /**
  * Checks the docs source for things that break for readers: links to pages or
  * sections that don't exist, links through a redirect, broken redirects, pages
- * missing from the sidebar, missing images and mismatched release-note versions.
+ * missing from the sidebar, missing images, mismatched release-note versions and
+ * repeated release-note sections.
  *
  * It reads only this checkout (no build, no network) and runs in a few seconds.
  * Any problem fails the check. The rules are the ones in AGENTS.md.
@@ -325,8 +326,14 @@ const NOTES = path.join(PAGES, 'release-notes.mdx')
 if (fs.existsSync(NOTES)) {
   const lines = text.get(NOTES).split('\n')
   const seen = new Map()
+  const sections = new Map()
   let current = null
   lines.forEach((line, i) => {
+    const s = line.match(/^##\s+(.+?)\s*$/)
+    if (s) {
+      if (sections.has(s[1])) report(NOTES, i + 1, `"## ${s[1]}" appears twice (also on line ${sections.get(s[1])})`)
+      else sections.set(s[1], i + 1)
+    }
     const h = line.match(/^#{2,4}\s+(.+?)\s+v(\d+\.\d+\.\d+)\b/)
     if (h) {
       current = { product: h[1].trim(), version: h[2], line: i + 1 }