U09955 Decision Journal Maintenance For Accessibility Services

Deterministic Workflow Constraints

• Replay score variance: <= 0.005 absolute per item.
• Artifact hash drift for identical replay: 0 allowed.
• Time-dependent fields allowed only in metadata and excluded from scoring.

Validation Gates

1. schema-gate — all required fields present and schema-valid; otherwise block and return error bundle.
2. determinism-gate — replay output within tolerance; otherwise quarantine and escalate.
3. policy-risk-gate — policy and risk checks pass; otherwise block routing.
4. approval-gate-high-risk — if risk is high, require human sign-off token; otherwise fail closed.

Handoff Contract

• Inputs: source-tagged signals, claims, evidence, confidence traces, run context.
• Outputs: deterministic artifact, scorecard, and handoff envelope with approval metadata.
• Routing rule: forward only when every gate passes; high-risk requires explicit sign-off token.

Immediate Hardening Additions

• Fixture: fixtures/minimal-valid.json
• Regression case: tests/regression-case.md
• Machine-readable summary: hardening-summary.json