Add governance reference control plane

[NavinAgrawal]

Summary

• add local governance reference-control-plane flow
• wire CLI and Make target
• update governance docs and roadmap

Verification

• private make precommit PYTEST_WORKERS=0: 1361 unit, 151 journey, 0 failed, 0 skipped
• private maintainer-violations: total 0, critical 0, high 0, medium 0, low 0, advisories test_file_sizes=12
• private maintainer-grade-quality: A+ 100.0
• public make precommit PYTEST_WORKERS=0: 1361 unit, 117 journey, 0 failed, 0 skipped
• public maintainer-violations: total 0, critical 0, high 0, medium 0, low 0, advisories test_file_sizes=12
• public maintainer-grade-quality: A+ 100.0