- Implemented pure CRM domain slice in `packages/domain/src/index.ts:1` (companies, contacts, opportunities + stage transitions, tasks, notes, `buildDashboardSummary`).
- Implemented in-memory application API in `packages/api/src/index.ts:1` (`createInMemoryCrmApi`, deterministic IDs, injectable clock, `ApiError` wrapping domain validation).
- Added focused tests in `packages/domain/test/domain.test.ts:1` and `packages/api/test/api.test.ts:1`.
- Wrote docs: `docs/prd.md:1`, `docs/acceptance-criteria.md:1`, `docs/architecture/domain-model.md:1`, `docs/api-contracts.md:1`, `specs/invariants.md:1`, `docs/handover.md:1`, `docs/test-strategy.md:1`, updated `README.md:1`.
- Verified workspace passes: `npm run lint`, `npm run typecheck`, `npm run test`.