Local的StreamingShell不支持windows执行command

描述：Local的StreamingShell不支持windows执行command

步骤：
1、windows下使用Local的StreamingShell执行command提示failed to start command: exec: \"/bin/sh\": executable file not found in %PATH%
2、查看代码中是写死的/bin/sh
`func (s *Local) initStreamingCmd(ctx context.Context, command string)`
`cmd := exec.CommandContext(ctx, "/bin/sh", "-c", command)`

期望：windows下可以使用
版本：latest

Start at Local.initStreamingCmd(ctx, command), where the issue identifies the hard-coded /bin/sh invocation. Reproduce the failure on Windows and inspect the surrounding Local StreamingShell implementation for platform-specific command execution expectations. Done means a Windows Local StreamingShell can execute a command successfully without the /bin/sh executable error, while existing behavior remains intact.

Written by the indexing model from the issue text.