Governance Narrative Engine for Human-AI Decision Substrates: Cryptographically Committed, Deterministic Audit Storytelling | APR-Lite Phase 20 — Technical Note

This record documents Phase 20 of APR-Lite, a governance engine protecting human decision authority from AI-influenced outputs in regulated industries. Phase 20 introduces the Governance Narrative Engine: a public, paginated, GLOBAL-signed surface that translates raw governance events into a chronologically ordered, human-readable account of how a tenant’s governance state evolved over time. Phases 14–19 established that every governance act is signed, chained, snapshotted, and independently verifiable. Phase 20 answers the question those phases cannot: “How did we get here?” The narrative surface converts the substrate’s cryptographic record into an auditable story. Each narrative unit corresponds to a governance event and carries deterministic template-driven prose per action type, a cryptographic commitment, and an optional signed receipt for Phase 14+ events. Topology context is populated only where constitutionally sourced — no topology fields are inferred or estimated. The response includes a GLOBAL-signed manifest committing to the narrative: event count, proof completeness status, and a cryptographic commitment over all narrative units. The manifest is independently verifiable through the Phase 18 federation surface without modification. A principal who receives a narrative cannot later claim it was selectively composed — the GLOBAL signature binds the narrative to the specific set of governance events it represents. Implementation note: a variable shadowing defect was identified and corrected during validation — documented here for reproducibility. Final verified state: 10/10 Phase 20 smoke tests passing. Worker version 8.2.0-p20.8.