PYTEST.md: focused on the core TDD loop (red-green-refactor), simple
assertions, and basic project setup. Suitable for learning TDD.
PYTEST-ADVANCED.md: adds fixtures, Flask/Quart test patterns,
parametrize, and mocking for when the basics are comfortable.
Embed Flask security recommendations inline instead of relying on URL
fetching at runtime. Add structured sections for resource limits, XSS,
CSRF, security headers, CSP, cookies, secrets, CORS, host validation,
and additional checks. Include a grading rubric for audit summaries.