Implement proof-claim and neuro-symbolic reasoning contracts

[mdheller]

Scope

Implement Holmes-side contracts for the SocioProphet governed-intelligence reference architecture.

Holmes owns the reasoning layer: typed claims, proof certificates, contradiction reports, explanation traces, textual entailment, rule traces, and adapters for neuro-symbolic reasoning.

Parent coordination issue: SocioProphet/sociosphere#310
Schema root issue: SocioProphet/ontogenesis#77

Canonical loop

Observe -> Anchor -> Normalize -> Propose -> Explain -> Verify -> Govern -> Act -> Receipt -> Learn

Holmes owns the Propose -> Explain -> Verify segment for claims.

Required objects to consume or expose

• Claim
• ProofCertificate
• ExplanationTrace
• ContradictionReport
• TruthBounds
• ReasoningTrace
• VectorCandidate as candidate input only
• PolicyDecision as downstream admission status, not owned by Holmes

Required design

A model, parser, graph query, or vector-symbolic result may propose a claim, but Holmes must not mark it admitted. Holmes should produce verification/explanation artifacts that Policy Fabric can evaluate.

Formal invariant:

VectorCandidate | ModelOutput | GraphCandidate -> ProposedClaim -> ExplanationTrace + ProofCertificate? + ContradictionReport

Then Policy Fabric decides: allow | deny | require_review | provisional.

Acceptance criteria

• Add a Holmes reference document describing the proof-claim contract and repo boundaries.
• Define or map Claim, ProofCertificate, ExplanationTrace, ContradictionReport, and TruthBounds to Ontogenesis canonical contracts.
• Add a worked example: technical document span -> proposed platform claim -> explanation trace -> contradiction report -> policy-ready claim.
• Add a worked example: vector candidate -> candidate claim -> verification/rejection path.
• Define a minimal reasoning trace format with rule names, premises, conclusion, evidence refs, and confidence/truth bounds.
• Document that vector-symbolic candidates remain candidate_only until evidence/proof/policy admission.
• Update README/catalog so Sherlock, GAIA, and Agentplane can discover Holmes contract responsibilities.

Validation

• Add a static fixture or schema example validating the worked examples if the repo has a test harness.
• If there is no harness, add fixture JSON/YAML plus a deterministic validation note listing expected fields.

Non-goals

• Do not implement Sherlock retrieval.
• Do not implement Policy Fabric admission decisions.
• Do not implement Agentplane runtime execution.
• Do not invent divergent schemas when Ontogenesis canonical contracts exist.

Dispatch note

Bounded first PR should focus on contract docs, examples, fixtures, and validation hooks. No broad reasoning-engine rewrite in this issue.