Stability checkpoint stable-v1.0.28 (svc) — Phase 4.2 wave continued: 17 CustomerService unit tests covering ALL public methods (CRUD + cursor pagination + batch import + search) with 6 mocked collaborators. Pin the create() side-effect contract end-to-end (repository + Kafka event port + WebSocket + SSE + recent buffer + audit). Cumulative svc Phase 4.2: 237 tests across 26 test files. Post-merge main pipeline #714 SUCCESS.