v3.6.85

Fixed

• Pre-close verification gate prevents workers from closing issues against unrelated PRs (GH#17372)
• New verify-issue-close-helper.sh validates PR diff touches files mentioned in issue body before allowing automated close
• Integrated verification into close_issues_with_merged_prs() and reconcile_stale_done_issues()
• Added mandatory pre-close verification gate to full-loop worker instructions