style: add missing newlines at end of files

Add newlines at end of JSON example files and batch script
for consistent formatting.

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

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

test_wsl_setup.bat

@@ -78,4 +78,4 @@ echo         "GEMINI_API_KEY": "your-key-here"
 echo       }
 echo     }
 echo   }
-echo }
+echo }