Flaky integration tests: PermissionError: Unauthorized

[PythonFZ]

Description

Two integration tests intermittently fail with PermissionError: Unauthorized in CI. They pass locally and on re-run — classic flaky behavior.

Affected tests

• tests/zndraw/test_edit_lock_integration.py::test_lock_holder_can_modify (observed on Python 3.11)
• tests/zndraw/worker/test_per_room.py::test_guest_can_register_room_job (observed on Python 3.13)

Error

Both fail with:

PermissionError: Unauthorized

Raised from the client's raise_for_status() method when the server returns 401.

Context

• Observed in PR feat: consolidate zndraw-auth + zndraw-joblib into monorepo #894 CI run #23563396485
• Python 3.12 passed all tests in the same run
• Different tests fail on different Python versions — not deterministic
• Both tests spin up real uvicorn servers and authenticate via JWT tokens
• Likely cause: auth token timing, server startup race, or Redis state leaking between tests

To investigate

• Check if test_settings autouse fixture properly isolates env vars between tests
• Check if Redis is fully flushed between server-based integration tests
• Check JWT token expiry / clock skew under load
• Try adding explicit server readiness checks beyond just /v1/health