ci.yml release job doesn't read docs/CHANGELOG.md -- GitHub Release notes are auto-generated only

[man4ish]

Summary

ci.yml's release job creates the GitHub Release automatically on a
v*.*.* tag push via softprops/action-gh-release@v2, but its body:
is a hardcoded template (downloads table + install commands) combined
with generate_release_notes: true (GitHub's own auto-summary of merged
PRs/commits since the last tag).

It never reads docs/CHANGELOG.md. The curated, verified changelog
entries maintained there (see the v0.7.1 entry, for example) do not
appear anywhere in the actual GitHub Release notes.

Impact

Every release currently ships with generic auto-generated release notes
on GitHub, while the real, curated summary of what changed lives only in
docs/CHANGELOG.md — a human has to remember to paste it in manually
after each release, or it just doesn't happen and the two diverge.

Options

1. Manual step (short-term): after each tag/release, manually copy the
   relevant docs/CHANGELOG.md section into the GitHub Release body.
2. Automate it (real fix): have the release job in ci.yml extract
   the current version's section from docs/CHANGELOG.md (the same kind
   of extraction disabled/release.yml already attempted — see disabled/release.yml: changelog-extraction awk pattern breaks on unbracketed version headings #88 for
   the bug in that specific implementation) and pass it as body: instead
   of, or prepended to, the current hardcoded template.

Priority

Low/medium — no functional impact, but a documentation/process gap worth
closing before this becomes a recurring manual step nobody remembers.