engine/ could create, edit, merge, resubmit and comment on a pull but not close
one. The appview's Close button is an htmx POST to /pulls/{n}/close. This tool
posts it with the session cookie, optionally posts one comment first (the rule
for the site-concurrency series' phase 8: every closed pull names its
successor), refuses to close a MERGED pull, and trusts nothing — it re-fetches
the pull page and requires the badge to read Closed.
First use: lichen.page.review #397-#399, three duplicates of #396.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E3aQXnUnx9kncNHQi3c92f
