ci(release): audit guard collection fails without project dependencies

Start with the tag-only audit command in .github/workflows/publish-pypi.yml and the bare-interpreter setup in scripts/audit_candidate.sh, then read tests/conftest.py and tests/test_runtime_audit_report.py. Reproduce the Azure import failure by running the report tests in an interpreter with only pytest installed. Done means the guard tests pass there, the workflow runs in a clean environment in PR CI, and the remaining tag-only commands are reviewed. Linked pull request #625 already targets this, so coordinate with it before starting.

Context

Publishing v0.17.0 is blocked by the tag-only runtime audit guard step, not by a vulnerability finding. In publish run 41312202572, all four Candidate runtime audit jobs failed: Python 3.11 job 124865052986, 3.12 job 124865053000, 3.13 job 124865053013, and 3.14 job 124865052979.

The Python 3.11 log records:

No known vulnerabilities found
runtime audit clean: 8 dependencies
ImportError while loading conftest '.../tests/conftest.py'.
tests/conftest.py:18: from azure.functions import HttpRequest
ModuleNotFoundError: No module named 'azure'
Process completed with exit code 4.

The minimal reproducer is the workflow's python -m pytest -o addopts= tests/test_runtime_audit_report.py in an interpreter with pytest but without project dependencies. scripts/audit_candidate.sh installs the candidate into a separate temporary venv, leaving the selected interpreter bare. Pytest then automatically loads the shared Azure-dependent conftest, even though the report tests use only pytest, its built-in tmp_path, and the standard-library-only audit report checker. PR CI installs project dependencies and therefore hides this tag-only failure.

Isolate the guard tests from the project conftest and exercise the workflow command in a dependency-less environment in PR CI. Priority is high because publication is blocked; size is XS (focused workflow change, regression tests, local validation and CI). The open backlog is empty and no duplicate audit/conftest defect was found; this release blocker should be addressed first.

Acceptance Checklist

• Reproduce the old command's Azure conftest import failure on Python 3.11 and 3.12, then verify the corrected command passes on both.
• The tag audit guard runs all report tests without installing unrelated project dependencies, retaining repository-root imports.
• PR CI contains a regression that fails for the old workflow command in a clean interpreter.
• make check-all and make build pass with coverage at least 95%.
• Review the remaining tag-only commands for the same bare-interpreter defect and document findings.

Out of scope

• Changing audit logic, advisory policy, release versions, release configuration, or publishing permissions.
• Retrying or moving v0.17.0, merging this fix, or performing publication. Fix forward on main; never move or reuse a tag for changed code.
• Refactoring unrelated raw workflow commands or changing downstream repositories.

References

• Failed publish run 41312202572
• Python 3.11 audit job 124865052986
• .github/workflows/publish-pypi.yml, scripts/audit_candidate.sh, tests/conftest.py, tests/test_runtime_audit_report.py, and pyproject.toml on main at 3379eb6.
• Pytest collection options: --noconftest disables conftest loading; pythonpath paths remain relative to rootdir.