Validation Evidence Contracts

Core exposes typed contracts only. Module runtimes own command flags, evidence file persistence, and rendering.

• EvidenceEnvelope derives PASS, PASS_WITH_ADVISORY, or FAIL and its CI exit code from typed result summaries.
• ArtifactRecord, ArtifactLink, and build_artifact_index(...) provide a generic, deterministic, JSON-serializable index for normalized inputs from requirements, architecture, specifications, code, tests, contracts, and other adapters.
• The index classifies unlinked artifacts, dangling links, duplicate identities, and self-referential contradictions; rebuild results report changed and removed identities.
• requirements_to_artifact_records(...) is the first integrated adapter. Architecture and other inputs are optional; their absence does not create a finding.

Use these contracts as inputs to validation and governance modules; they do not introduce a specfact trace command, index-file persistence, or requirements authoring workflow.