fix(ci): add pyproject.toml so pytest can import data_quality package

[bdevierno1]

Root Cause

CI job Data-quality checks & contract lint was failing with:

ModuleNotFoundError: No module named 'data_quality'

at tests/test_data_quality.py:12 — pytest collection exit code 2.

The workflow sets working-directory: backend and runs:

pytest tests/test_data_quality.py -v

The data_quality package lives at backend/data_quality/ (has __init__.py), but there was no pytest path configuration telling pytest to include backend/ on sys.path. Pytest's default import mode inserts the test file's parent directory (tests/) into sys.path, which doesn't contain data_quality.

Fix

Add backend/pyproject.toml with:

[tool.pytest.ini_options]
pythonpath = ["."]

The pythonpath option (available since pytest 7.0; requirements pin pytest>=8.0.0) prepends the working directory (backend/) to sys.path before any test collection, making data_quality and sibling packages importable without a pip install -e . step.

Diff

One file added: backend/pyproject.toml (5 lines). No code changes.

Verification

pytest tests/test_data_quality.py -v
# 14 passed — all TestCompleteness, TestUniqueness, TestValidity,
#              TestFreshness, and test_contracts_load

Out of scope

This PR only adds the pytest path configuration. No logic or test changes are included. The DeprecationWarning for datetime.utcnow() surfaced in the run is pre-existing and tracked separately.

Links

• Fixes CI failure on PR Add data-quality checks, contracts, and CI for core datasets #5: Add data-quality checks, contracts, and CI for core datasets #5
• Failed run: https://github.com/bdevierno1/Vecna-Operations-Console/actions/runs/27798199236