tests/ contains the supported open-source regression suite. These tests run
in CI and cover the SDK surface that ships publicly.
legacy_tests/ preserves the original internal suite. Those tests exercise
tightly coupled infrastructure (MCP, remote services, etc.) and are excluded
from the default run. Execute them manually via pytest legacy_tests when the
required services are available.
Fixtures live in tests/conftest.py and are shared by both suites.
