Align StageFabric success evidence semantics

[aantenore]

What changed

• mirror the finalized StageFabric successful-run trace as a closed TypeScript and AJV union
• allow only completed events or pre-output retries with status 429, 502, 503, or 504
• reject terminal failure reasons, arbitrary status codes, missing retry codes, and codes on completed events
• exercise a real 503 retry in package and CLI consumer smoke
• retain the byte-identical golden artifact and point its provenance to reachable StageFabric main commits

Why

The initial consumer adapter was more permissive than the finalized producer contract. A lineage consumer must never accept evidence the producer itself can no longer emit.

Impact

AgenticStrata and StageFabric now share the same successful-run evidence semantics while preserving the existing Passport v2 bytes and golden digest.

Validation

• npm run release:check: 92 tests; 92.32% statement coverage
• production audit: 0 vulnerabilities
• publint, type surface, package consumer, and CLI smoke passed
• repository identity and forbidden-literal audit across all refs passed