#52's IssueTracker spec is CloseIssue(repo, number, comment). Refine the
#51 port signature to match and have the service pass the ticket body as
the closing comment (empty ⇒ close only). Keeps the close-with-comment
flow first-class rather than forcing two separate ticket items.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>