docs verify: DEVELOPMENT.md in STAGE_READMES; self-labelling release notes; prose corrections to 4.6.0 (#47 Block 3)

Files changed:
- .gitea/workflows/release.yml
- CHANGES.md
- VERSION
- instructions/dev/stack-close/SKILL.md
- tools/CONTRACT.md
- tools/chemenu/commands/docs_verify.py
- tools/chemenu/commands/git_publish.py
- tools/chemenu/tests/test_docs_verify.py

.gitea/workflows/release.yml

@@ -102,11 +102,32 @@ jobs:
       - name: Release notes from CHANGES.md
         # `version notes` fails when the changelog has no entry for this
         # version, which is the last place that mistake can still be caught.
+        #
+        # The footer below settles Gitea #47's second side-finding: a release
+        # note is written once, at tag time, and a later correction to
+        # CHANGES.md never reaches it - `gitea-mcp` has no release-edit method,
+        # and delete-and-recreate would destroy the attached tarball assets that
+        # INSTALL.md and `version check` point at. That happened for real to
+        # v4.4.0, whose note carried a fact that the corpus had already
+        # corrected. Rather than build a correction path for a text nobody can
+        # edit, the snapshot says it is one and names where the maintained
+        # version lives. A stale note then costs a reader one click instead of
+        # a wrong belief. Appended here rather than inside `version notes`,
+        # which is a general-purpose extractor whose other callers (a local
+        # preview, a pipe) should not inherit a release-page footer.
         if: steps.version.outputs.skip != 'true'
         run: |
           set -eu
           tools/wikitool docs verify
           tools/wikitool version notes > /tmp/release-notes.md
+          cat >> /tmp/release-notes.md <<'EOF'
+
+          ---
+
+          *This note is a snapshot of the `CHANGES.md` entry as it stood when the tag was cut, and
+          is never edited afterwards. The maintained version of this text - including any later
+          correction - is the entry for this version in `CHANGES.md` in the repository.*
+          EOF
           cat /tmp/release-notes.md
 
       - name: Build the distribution tarball