🎯 Adoption Sweep - SKILL.md Compat Floors

Toggle the state to see the before/after impact of this playground PR (the adoption-sweep that closes the M170 thread).

Floor distribution

PR closes the M170 thread end-to-end: #1961 spec → #1962 supersede → #1968 check (WARN) → this PR (sweep + STRICT).

Once merged, the floor consistency test in tests/manifests/test-cc-version-floor.sh defaults to STRICT mode — future PRs cannot ship a skill whose compatibility: floor is below the project SoT (currently 2.1.139).