# CHANGELOG v0.4

## Added

- `active_causal` mode using binary reward only.
- Joint Bayesian posterior over task hypothesis and opaque partner probe permutation.
- Joint probe/intervention expected-information-gain selection.
- Posterior pairwise task-equivalence probabilities.
- OOD partner permutation benchmark.
- Counterfactual relaxation search for infeasible configurations.
- `HIPG-CERT-0.4` JSON Schema validation.
- SHA-256 input/result/certificate lineage.
- Restricted typed contract DSL for permission/scope preservation.

## Preserved

- All v0.3 benchmark modes through compatibility core.
- Explicit terminal lower-bound / structural branches.
- SUCCESS / INFEASIBLE / UNKNOWN separation.