Add comprehensive unit tests for Business Core modules:
- Partners: 22 tests (CRUD, filters, tenant isolation)
- Products: 23 tests (CRUD, categories, search)
- Invoices: 31 tests (CRUD, payments, state transitions)
- Warehouses: 24 tests (CRUD, locations, default handling)
- HR Employees: 24 tests (CRUD, terminate/reactivate, subordinates)
Test infrastructure:
- jest.config.js with ts-jest and ESM support
- setup.ts with mocks for AppDataSource and database
- helpers.ts with factory functions for test data
Total: 114 tests passing
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>