[emmanuel-a-otchere]

Summary

• Implement the Layer 3 (Business Guardrails) module src/layer3/layer3.ts per RFC-0003 and the v0.4 contract:
  • parseRules: the guardrail DSL parser (rule <id> { when <condition> then <reject|annotate|escalate> with rationale "..." }). Malformed rules throw guardrail-rules-malformed
  • Condition language (v0.4): constraint(<scope>) == / != "<value>", flag(<flag_type>), source_expired(), decision_type == "<suffix>"
  • Layer3.evaluate: evaluates rules against a post-Layer-2 COTS, attaches a GuardrailDecision to every decision (accepted / rejected / annotated / escalated), applies the normative status updates (rejected -> superseded, escalated -> appealed), and returns the rejected/escalated lists. No silent rejection: rejected decisions remain in the COTS with their rule and rationale
  • Empty/missing rule sets throw domain-rules-missing per the contract's failure modes
• Add the GuardrailDecision types to src/cots.ts (COTS schema v1.3.0; optional field)
• 9 new tests: parser (well-formed, malformed, unknown condition) and evaluator (binding rejection with status update, advisory annotation, escalation, acceptance with recorded rationale, empty rules, no-silent-rejection)

Verification

• npx vitest run: 30/30 tests pass
• npx tsc --noEmit: clean