fix(evaluators): preserve refinement validation across loky transport

[isty2e]

Refinement-bearing local-search results could fail to deserialize when returned by Joblib's loky workers. The alignment cache stored candidate identities that pickle does not preserve for large integers or floats. Existing small-integer tests masked the failure.

Changes

• Transport references to the validated request/refinement owners rather than raw candidate identities, without serializing equality callables.
• Restore through the normal constructor. Stale owner references still require revalidation, and the coordinator independently checks alignment before assimilation.
• Update the worker guide and evaluator contracts for development-version support, while retaining the threading workaround for 0.2.0.

Behavioral Evidence

A two-process CSA hill-climb run with candidates in [1000, 1100] now matches sequential execution in both per_request and worker_session modes, including candidate order, refinement provenance, evaluation costs, and final optimizer state.

Regression tests cover pickle protocols 4 and 5, large integers and floats, request-aligned payloads, replaced validation owners, invalid accounting, and coordinator rejection of mutated custom candidates. The guide examples also run with both loky transport modes.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-26T06:24:03.186021Z	baf8886	PR opened

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