- Add gt mq command group with reject subcommand - Add FindMR method to locate MRs by ID or branch - Add RejectMR method to reject MRs with reason - Add notifyWorkerRejected for optional mail notification - Add tests for rejection state transitions Closes gt-svi.5 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>