Bug: SSH connection fails when targeting Windows host due to hardcoded 'sh' wrapper (corrupted CP949 error `'sh'() Ǵ...`)

[Laser-Cho]

Description

When attempting to connect or reinstall a connection (wsh conn reinstall) to a remote target that runs on Windows OS (with native OpenSSH server enabled), the process fails during client platform detection. The terminal prints a corrupted, unreadable error message:

Error: reinstalling connection: error detecting client platform: error running uname -sm: Process exited with status 1, stderr: 'sh'()  Ǵ  ,     α, Ǵ ġ  ƴմϴ.

Root Cause Analysis

1. Decoding Error (CP949 to UTF-8)
   The unreadable message 'sh'() Ǵ , α, Ǵ ġ ƴմϴ. is the CP949-encoded Windows Command Prompt/PowerShell error message decoded as UTF-8 in Go. The original Korean error message is:
   'sh'은(는) 내부 또는 외부 명령, 실행할 수 있는 프로그램, 또는 배치 파일이 아닙니다.
   (English translation: 'sh' is not recognized as an internal or external command, operable program or batch file.)

2. Hardcoded sh -c wrapper
   In the Go source code, when detecting the platform of the remote machine:

• In pkg/remote/connutil.go inside GetClientPlatform, uname -sm is run to determine the target OS and architecture.

• However, in pkg/genconn/genconn.go inside BuildShellCommand, all remote shell commands are wrapped in sh -c by default:

  return fmt.Sprintf("sh -c %s", shellutil.HardQuote(envVars.String()+shellCmd)), nil

• Since a Windows host does not have sh installed in its %PATH% by default, executing sh -c 'uname -sm' fails immediately with the Windows command-not-found error.

Environment

• Client OS: Windows/Linux/macOS
• Remote Target OS: Windows (running OpenSSH)
• Wave Terminal / wsh version: v0.14.5

Suggested Mitigation / Fixes

• Detection fallback: If sh fails or is missing, try executing commands via cmd.exe /c or powershell -Command when targeting Windows hosts, or allow specifying the shell/OS configuration beforehand.
• Graceful parsing: Handle different shell error codes and decoding errors (like CP949 fallback for Windows targets) to show friendly messages when the shell invocation fails.