Run only unit tests in CI test stage

Integration tests require Docker Compose services (PostgreSQL, MinIO, Redis)
which aren't available in the CI container. Unit tests run independently.

.gitlab-ci.yml

@@ -33,7 +33,8 @@ python_tests:
     - pip install pytest pytest-asyncio pytest-cov httpx
   script:
     - cd backend
-    - python -m pytest -v --cov=app --cov-report=term --cov-report=xml:coverage.xml --cov-report=html:coverage_html --junitxml=pytest-report.xml
+    # Only run unit tests - integration tests require Docker Compose services
+    - python -m pytest tests/unit/ -v --cov=app --cov-report=term --cov-report=xml:coverage.xml --cov-report=html:coverage_html --junitxml=pytest-report.xml
   artifacts:
     when: always
     expire_in: 1 week