Change contract: enable exact JSON f64 roundtrips for ploy-research checkpoint state so a freshly written content-addressed MCTS checkpoint validates after typed readback.
Acceptance evidence:
- A focused counterexample roundtrips
-1.9089014592447406_f64 through the configured serde_json graph without changing to_bits().
- The authenticated selection checkpoint readback test covers that nontrivial reward and passes.
- Existing focused prediction MCTS tests pass.
Dependency / merge order: predecessor to #325; merge this before promoting the three-event E2E fixture.
Out of scope: evaluator semantics, cohort partitioning, Polymarket projection, collector/runtime, hft-search-kernel behavior, or checkpoint schema changes.
Rollout / rollback: dependency-feature-only correctness change; rollback restores the known false corruption rejection for valid floating-point metrics.
Observed failure: -1.9089014592447406_f64 serializes and parses one ULP apart under the current feature graph, so authenticated_selection_evidence reports selection checkpoint does not match the current durable state even though the persisted state and referenced artifact are otherwise identical.
Change contract: enable exact JSON f64 roundtrips for ploy-research checkpoint state so a freshly written content-addressed MCTS checkpoint validates after typed readback.
Acceptance evidence:
-1.9089014592447406_f64through the configured serde_json graph without changingto_bits().Dependency / merge order: predecessor to #325; merge this before promoting the three-event E2E fixture.
Out of scope: evaluator semantics, cohort partitioning, Polymarket projection, collector/runtime, hft-search-kernel behavior, or checkpoint schema changes.
Rollout / rollback: dependency-feature-only correctness change; rollback restores the known false corruption rejection for valid floating-point metrics.
Observed failure:
-1.9089014592447406_f64serializes and parses one ULP apart under the current feature graph, soauthenticated_selection_evidencereportsselection checkpoint does not match the current durable stateeven though the persisted state and referenced artifact are otherwise identical.