fix: validate scorer instance names in config (#407)

* fix: validate scorer instance names in config

* fix: run scorer config tests in CI

* fix: drop redundant UV_PYTHON env and quote unittest pattern

* fix: report precise scorer name validation errors

.github/workflows/ci.yml

@@ -43,7 +43,9 @@ jobs:
       - name: Run tests
         env:
           PYTHONUNBUFFERED: "1"
-        run: uv run tests/run_tests.py 2>&1
+        run: |
+          uv run python -m unittest discover -s tests -p 'test_*.py'
+          uv run tests/run_tests.py 2>&1
 
       - name: Build package
         run: uv build