reform_validation_payload: embed executable reform dicts + publisher slugs for scorecard claim identity

The reform-validation registry is being consolidated into policyengine-scorecard (PolicyEngine/policyengine-scorecard#15, adapter in #16); calibration-diagnostics' External checks tab retires (calibration-diagnostics#140). The registry and producer stay here — release-exact scoring at each build's engine pins is engine-adjacent work — but the artifact becomes a scorecard input, which exposes two gaps in reform_validation.json:

1. No executable reform dicts. Scorecard claims key off a ReformRef; with only a row id available, scored rows use policy_ref descriptors ({"policy": "ks_hb2620_eitc"}). The param dicts already exist in state_reforms.json — emitting each row's reform_params (and non-current-law baseline where applicable, e.g. the OBBBA suite's TCJA-expiration counterfactual) upgrades claims to framework="policyengine_us", making identical policy worlds share a reform key across sources (JCX-35-25 rows could then resolve against the scorecard's harvested JCT claims instead of coexisting as duplicates).

2. No publisher slugs. The scorecard derives publishers from citation strings ("CA FTB…" → ca_admin); a benchmark_publisher field per spec (e.g. ks_lrd, ct_ofa, jct, census) would make source attribution exact instead of heuristic.

Both are additive to schema v1 (consumers ignore unknown keys). Happy to PR this once the scorecard-side design questions in PolicyEngine/policyengine-scorecard#15 settle.

🤖 Generated with Claude Code

Start by locating the code that produces reform_validation.json and reading the existing state_reforms.json data used for reform_params. Review policyengine-scorecard#15 and #16 before changing the schema, then verify that each emitted row contains the applicable reform data and benchmark_publisher while remaining compatible with schema v1 consumers.