[Desktop][Windows] Bash tool fails with Wsl/Service/CreateInstance/E_ACCESSDENIED while CLI works

Summary

OpenCode Desktop on Windows cannot execute commands through its built-in
bash tool. OpenCode CLI works correctly on the same machine.

The failure occurs when Desktop tries to start:

C:\Windows\System32\bash.exe

This executable returns:

Wsl/Service/CreateInstance/E_ACCESSDENIED

OpenCode Desktop then displays:

"Shell Failed"

and reports that the bash tool returned an internal argument error.

Environment

• OS: Windows 11
• OpenCode Desktop version: [add version]
• OpenCode CLI version: [add version]
• Provider/model: MiniMax-M3
• OpenCode Desktop backend: local Windows backend
• OpenCode CLI: works correctly on the same machine
• WSL: installed, but unavailable to the Desktop bash tool

Steps to reproduce

1. Open OpenCode Desktop on Windows.

2. Start a session using MiniMax-M3.

3. Ask the agent to execute:

   Get-Date

4. Ask it to execute:

   echo HOLA-DESDE-OPENCODE

Actual behavior

The Desktop bash tool fails repeatedly and displays:

Shell Failed

The assistant reports:

"The bash tool is returning an internal argument error."

Running bash or wsl directly from PowerShell produces:

Wsl/Service/CreateInstance/E_ACCESSDENIED

Expected behavior

The built-in bash tool should execute commands successfully on Windows,
or OpenCode Desktop should provide a way to select PowerShell as the
Windows shell.

Additional observations

• PowerShell itself works correctly:

  powershell.exe -NoProfile -Command "Get-Date"

• OpenCode CLI works correctly on the same machine.

• Serena works, but it runs inside a Docker/Linux container and is not
  equivalent to executing commands on the Windows host.

• Serena returns Linux/UTC output because it runs inside Docker.

• The session does not become corrupted and no orphaned tool_use is
  observed. Therefore this is different from issue #21489.

• This is not a WSL-hosted OpenCode server and no UNC project path such as
  \wsl.localhost\Debian is involved. Therefore this is different from
  issue #19473.

Related issues

• #19473 - Desktop app sends UNC paths to a WSL-hosted server
• #21489 - Aborted bash calls can corrupt the session