[Windows] Shell commands have no console handle since v1.0.57 - breaks Clear-Host and MSAL interactive auth

[chitturs]

Describe the bug

Since upgrading from v1.0.47 to v1.0.60, the powershell tool launches pwsh.exe without a console handle attached to the process. This breaks any script that calls Clear-Host/cls or requires MSAL interactive browser authentication.

Evidence from inside a powershell tool call:

# GetConsoleWindow() returns 0 (no console window)
Add-Type -TypeDefinition 'using System; using System.Runtime.InteropServices; public class C { [DllImport("kernel32.dll")] public static extern IntPtr GetConsoleWindow(); }'
[C]::GetConsoleWindow()   # 0

[System.Console]::WindowWidth  # Throws "The handle is invalid"
Clear-Host                     # Throws SetValueInvocationException: "The handle is invalid"

# Process has no window
[System.Diagnostics.Process]::GetCurrentProcess().MainWindowHandle  # 0

Affected version

GitHub Copilot CLI 1.0.60-0.

Last working version: 1.0.47 (May 13, 2026).

Steps to reproduce the behavior

1. Launch Copilot CLI v1.0.60 on Windows
2. Ask it to run a command containing cls or Clear-Host (e.g., "run cls; Write-Host hello")
3. Observe exit code 1 with error:

SetValueInvocationException:
Line |
   3 |  $RawUI.CursorPosition = @{X=0;Y=0}
     |  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     | Exception setting "CursorPosition": "The handle is invalid."

Alternatively:

1. Ask it to run any script that uses MSAL interactive auth (e.g., Azure EV2 deployment cmdlets)
2. Auth fails with:

Failed to get authentication information : Value cannot be null. (Parameter 'format').

No browser window opens for authentication.

Expected behavior

Shell commands executed via the powershell tool should have a console handle attached, as they did in v1.0.47. Clear-Host should succeed or be a silent no-op, and MSAL should be able to open a browser for interactive authentication.

Additional context

• Operating system: Windows 11 (10.0.26100)
• CPU architecture: x86_64
• Terminal emulator: Windows Terminal
• Shell: PowerShell 7.6.2
• The pwsh process is launched as: pwsh.exe -NoProfile -NoLogo -NonInteractive -Command "..."
• The Copilot shell wrapper's finally block checks $? and calls $host.SetShouldExit(1) on any error, making the cls error fatal
• Workaround: use Start-Process pwsh -ArgumentList @("-ExecutionPolicy", "Bypass", "-Command", $cmd) to get a real console window, but this prevents the agent from capturing stdout directly
• Possibly related: Bug: CLI produces no stdout in child process (Start-Process) on Windows — blocks headless automation #2525