Governance Orchestrator: A Vendor-Agnostic Infrastructure Attestation Schema for Substrate Governance Systems

Current AI governance architectures treat hardware attestation and substrate pattern governance as separate concerns requiring deep integration. This paper proposes a Governance Orchestrator pattern that decouples these layers through a vendor-agnostic infrastructure attestation schema. The Orchestrator accepts two event classes -- APR events from substrate pattern governance and INF events from any hardware attestation, entropy, or TPM module -- normalizes them into a single unified schema, and writes both to a shared immutable audit log. This approach eliminates vendor lock-in, preserves substrate governance ownership, and enables any hardware attestation implementation to interoperate with clinical AI governance systems by conforming to a minimal shared schema. The INF-* event standard defined here establishes a stable interface between the hardware truth layer and the substrate pattern governance layer without requiring either layer to depend on the other's implementation details.