Ratify claims[] additive field in contracts.ts (lockstep across all 4 repos)

[gnanirahulnutakki]

Background

Per docs/spec.md §9.2, a richer claims?: ClaimProvenance[] field on SynthesizedArticle is a proposed additive field that would surface per-claim provenance on the wire.

Current state

• ClaimProvenance and ProvenanceMap are defined in src/provenance.ts (internal only).
• buildProvenance() builds the per-claim map and isFullyGrounded() gates on it internally in the synthesizer.
• The wire contract (contracts.ts) does NOT include claims? yet.
• Per-claim provenance IS enforced internally (ungrounded claims degrade the article) — the wire just doesn't expose it.

What needs to happen

1. Ratify the type across all 4 repos — additive fields need lockstep changes to contracts.ts in:
   • ardur-news-aggregator
   • ardur-ranking-engine
   • ardur-top10-engine
   • ardur-article-synthesizer (this repo)
2. Bump SCHEMA_VERSION? Additive = backward-compatible, so no schema-version bump required per ARCHITECTURE.md §5, but it should be coordinated.
3. Expose the field in SynthesizedArticle and wire buildProvenance() output into assembleArticle().

Notes

• The field should be typed as claims?: ClaimProvenance[] (optional, not required, for backward compat).
• The ClaimProvenance type from provenance.ts should move to or be mirrored in contracts.ts.
• This is a cross-repo change — do not add it unilaterally.

[gnanirahulnutakki]

Folded into the content-flow redesign design doc (ardur-pipeline/docs/redesign-content-flow-2026-06.md, ArdurAI/ardur-pipeline#14, §6.1): ClaimProvenance is promoted into contracts and exposed as SynthesizedArticle.claims?: ClaimProvenance[], re-keyed onto rev-3 ExtractedFact.id so the provenance gate and the source-trail UI share one type. Additive, no SCHEMA_VERSION bump. Type lands in contracts (ArdurAI/ardur-contracts#1); wired here in #13, which will carry Closes #6.