~x-ai/grok-latest → B (2:5)

B removes dual-path legacy projection (_legacy_commit_row/_legacy_observation and GitDiscovery-invented epoch/commit pages) so the ledger UI is Evidence-envelope-only, hardens Emission required fields, and updates tests accordingly—core durable design cleanup. A adds a useful CopyGardenRank POST /ui clipboard control with markdown formatting and solid unit/integration/browser coverage, but it is incremental UX polished on existing ranking render paths rather than a structural correctness win.