chore: prepare compression lab delivery

[douglasmonsky]

Summary

• add the approved Compression Lab design, roadmap, and implementation plan
• pin CI to the Agent Maintainer revision that honors Bandit baselines and domain-owned Tach modules
• add workflow concurrency and document trusted-publishing permissions
• exclude local Serena memories from Markdown lint

Validation

• uvx zizmor --offline --no-progress .github/workflows
• actionlint .github/workflows/*.yml
• markdownlint-cli2
• python3 scripts/check_release.py
• git diff --check