[Epic] read-audit-db-migration E2E Validation & Phase 2 Closeout

[Cho-Geer]

Epic: read-audit-db-migration E2E Validation & Phase 2 Closeout

Based on: docs/review/framework-refactor/read-audit-db-migration-plan.md
Document version: v1.4.0

Verify that read-audit DB migration (Phase 1 + Phase 2) is fully implemented and production-ready.

Sub-issues

• E2E-1: recordRead → DB-only write → verifyRead roundtrip #88 — E2E-1: recordRead → DB-only write → verifyRead roundtrip
• E2E-2: knowledge_cache_attest uses shared read-audit API #89 — E2E-2: knowledge_cache_attest uses shared read-audit API
• E2E-3: JSONL fallback when DB unavailable (N3) #90 — E2E-3: JSONL fallback when DB unavailable (N3)
• E2E-4: Migration script idempotency (N4) #91 — E2E-4: Migration script idempotency (N4)
• E2E-5: Self-test Check 40-43 all PASS

Acceptance criteria

• All 5 E2E scenarios PASS
• read-audit-db-migration-plan.md updated to v1.4.0
• Phase 2 confirmed complete (DB-only writes, JSONL read-only)