Tests verify:
- Single vendor stops after first success
- Multi-vendor stops after all primaries (even if they fail)
- Fallback vendors are not attempted when primaries are configured
- Tool-level config overrides category-level config
Tests use pytest with fixtures and mocked vendors, can run without API keys in CI/CD.
Run with: pytest tests/test_multi_vendor_routing.py -v
Youssef Aitousarrah