style: 代码格式化

tests/test_working_services.py

@@ -1,6 +1,7 @@
 """
 Working unit tests for service modules based on actual module structure.
 """
+
 import pytest
 
 # Version import commented out - actual module only has variables
@@ -86,4 +87,4 @@ class TestTTSService:
 
         # Test speak with empty string
         with pytest.raises(ValueError):
-            tts_service.speak("")
+            tts_service.speak("")