- Replace PostgreSQL AsyncPostgresSaver with MemorySaver in test fixtures
- Create test_app fixture with test_lifespan using in-memory dependencies
- Mock LLM model to avoid requiring API keys during tests
- Update test_api.py to use test_app fixture instead of production app
- Fix test_root endpoint URL to match root_path configuration
- All API tests now pass without requiring external services (0.06s vs 30s+ timeout)
This change allows tests to run in isolation without PostgreSQL or API keys,
making them faster and more reliable for CI/CD and local development.
