Execution artifacts

An execution artifact records what ran and how:

• links to corpus + vector fingerprints
• execution contract and plan fingerprint
• randomness audit (sources, budget)
• approximation + determinism reports
• execution signature tying all of the above

Portability guarantees:

• Artifacts are versioned; compatibility is enforced by the execution ABI.
• Replay does not require live vector sources; artifacts plus plan are sufficient.
• Backends must refuse execution if they cannot meet the artifact’s contract/metric.

Mutation rules:

• Artifacts are immutable once committed.
• Ledger retention may prune historical results but preserves chain hash integrity.

Docs → code

• src/bijux_vex/core/execution_result.py
• src/bijux_vex/core/abi/__init__.py
• src/bijux_vex/domain/execution_artifacts/