Update placeholder comments in engineer.go to clarify that: - ProcessMR and ProcessMRFromQueue are not used in production - Refinery agent uses git commands per role prompt - Removes references to tombstoned gt-3x1.2 and gt-3x1.4 issues 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>