Immutable Base SDK v3.1.2 role-contract release.
Provides the canonical base.challenge_sdk surface with:
- Role and capability registry contracts
- API/CLI manifests
- External result envelope
- SemVer compatibility helpers
- Runtime health/version schemas
- Production role guards
Wheel SHA-256: 3a61c2d3a343ed6de55e80215486e3de0c9639276443d08f2ed316bc807f2ff0
Commit: dec4f7d