ci: install matplotlib/seaborn for graphguard tests

.github/workflows/ci.yml

@@ -37,14 +37,17 @@ jobs:
       - name: Install CPU torch + torch-geometric
         run: |
           pip install torch==2.5.1 --index-url https://download.pytorch.org/whl/cpu
-          pip install torch-geometric>=2.4.0 numpy pandas scikit-learn
+          pip install "torch-geometric>=2.4.0" numpy pandas scikit-learn xgboost matplotlib seaborn
       - run: pip install -e ".[dev]"
       - name: Materialize graph from synthetic fallback
         run: |
-          python -m graphguard.download_data
-          python -m graphguard.build_graph
+          coverage erase
+          coverage run -m graphguard.download_data
+          coverage run --append -m graphguard.build_graph
       - name: Run tests with coverage
-        run: pytest tests/ -v --tb=short --cov=graphguard --cov-report=term-missing --cov-fail-under=30
+        run: |
+          coverage run --append -m pytest tests/ -v --tb=short
+          coverage report --show-missing --fail-under=30
 
   typecheck:
     # Gradual typing: mypy reports but does not block CI yet.