- Add pytest test suite across all modules (config, database, file_processor,
ai_processor, api, scheduler, monitoring, ftp_server)
- 145 tests covering normal paths, error handling, edge cases
- Mock external dependencies (AI endpoint, requests, pyftpdlib)
- 95% code coverage with fail-under=90 threshold in CI
- Update CI workflow to run pytest with coverage enforcement
- Add pyproject.toml with pytest/coverage configuration
