Fix MyPy type errors in tests

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: msch-nutrient

tests/integration/test_live_api.py

@@ -8,7 +8,7 @@
 from nutrient_dws import NutrientClient
 
 try:
-    from . import integration_config
+    from . import integration_config  # type: ignore[attr-defined]
     API_KEY = integration_config.API_KEY
     BASE_URL = getattr(integration_config, 'BASE_URL', None)
     TIMEOUT = getattr(integration_config, 'TIMEOUT', 60)

tests/unit/test_file_handler.py

@@ -52,5 +52,5 @@ def test_get_file_size_none():
     class DummyFile:
         pass
 
-    size = get_file_size(DummyFile())
+    size = get_file_size(DummyFile())  # type: ignore[arg-type]
     assert size is None