[quality] Add unit-test CI workflow for Python test helpers

[kubestellar-hive]

Finding

testing-lab has no unit test CI workflow. The repository contains testable Python helper modules — tests/service_catalog/shared/kube.py and various pytest test files — but there is no pytest run in CI. The only CI workflow is Argo YAML linting (.github/workflows/lint.yaml).

This means:

• Python syntax errors in test helpers are not caught until runtime in a live cluster
• Logic bugs in kube.py utilities (kubectl wrappers, pod selectors, HTTP probes) are never exercised offline
• Coverage cannot be tracked or gated

Recommendation

1. Add .github/workflows/unit-tests.yml that runs pytest tests/ -v on PRs and pushes to main
2. Install test dependencies (pytest, pytest-cov) in CI
3. Add unit tests for tests/service_catalog/shared/kube.py (mock subprocess.run to test kubectl wrappers offline)
4. Optionally add a coverage threshold gate

Priority

• Impact: high — test helper regressions go undetected until live cluster runs
• Effort: low — a basic CI workflow and mock-based unit tests can be added quickly

---

Filed by quality agent (hold-gated mode)

[hanthor]

Closing as duplicate of #175. This issue covers the same gap: Python test files exist but no CI workflow executes them.