PythonToCSharpConverter.cs:36 -- 移除未使用的 indentLevel 变量

Program.test.cs -- 将顶层语句改为 ManualTest.RunAsync() 方法，消除入口点冲突
BatchConversionService.cs:96 -- options 可空参数添加 ?? new ConversionOptions() 空值回退
Co-authored-by: monkeycode-ai <monkeycode-ai@chaitin.com>

CodePlay.Core/Converters/PythonToCSharpConverter.cs

@@ -33,7 +33,6 @@ public class PythonToCSharpConverter : IConverter
         sb.AppendLine();
         
         var lines = pythonCode.Split('\n');
-        var indentLevel = 0;
         
         foreach (var line in lines)
         {

CodePlay.Core/Services/BatchConversionService.cs

@@ -93,7 +93,7 @@ public class BatchConversionService : IBatchConversionService
                 
                 var sourceCode = await File.ReadAllTextAsync(sourceFile, cancellationToken);
                 var conversionResult = await _conversionService.ConvertAsync(
-                    sourceCode, sourceLanguage.ToName(), targetLanguage.ToName(), options);
+                    sourceCode, sourceLanguage.ToName(), targetLanguage.ToName(), options ?? new ConversionOptions());
                 
                 if (conversionResult.Success)
                 {