Shell detection fails for PowerShell 7 (pwsh) in non-admin mode on Windows

[khaled4vokalz]

Describe the bug

The _shell() method in config.js fails to detect PowerShell 7 (pwsh) when running without administrator privileges on Windows, because it only checks if process.title contains "powershell" but not "pwsh".

When running a CLI built with oclif in PowerShell 7 without admin privileges:

• process.title is "pwsh" (or similar)
• The shell detection falls through to COMSPEC, returning "cmd.exe"
• This causes @oclif/plugin-autocomplete to not display PowerShell setup instructions

When running the same CLI in PowerShell 7 with admin privileges:

• process.title includes "PowerShell" (e.g., "Administrator: PowerShell 7")
• Shell is correctly detected as "powershell"
• Autocomplete instructions display correctly

To Reproduce

1. Open PowerShell 7 (pwsh) without admin privileges on Windows
2. Run node -e "console.log(process.title)", outputs pwsh or similar (not containing "powershell")
3. Run any oclif CLI with the autocomplete plugin (e.g., mycli autocomplete)
4. Observe that PowerShell-specific instructions are not shown

    $ mycli autocomplete 
    Building the autocomplete cache... done
   
    Setup Instructions for MyCli CLI Autocomplete ---
    ==============================================
   
     Every time you enter <TAB>, the autocomplete feature displays a list of commands (or flags if you type --), along with their summaries. Enter a letter and then <TAB> again to narrow down the list until you end up with the complete command that you want to execute.
   
     Enjoy!

5. Open PowerShell 7 as Administrator
6. Run node -e "console.log(process.title)", outputs something containing "PowerShell"
7. Run the same autocomplete command
8. Observe that PowerShell instructions are now shown correctly

    $ mycli autocomplete
     Building the autocomplete cache... done
   
     Setup Instructions for MyCli CLI Autocomplete ---
     ==============================================
   
     1) Run these two cmdlets in your PowerShell window in the order shown:
   
       New-Item -Type Directory -Path (Split-Path -Parent $PROFILE) -ErrorAction SilentlyContinue
       Add-Content -Path $PROFILE -Value (Invoke-Expression -Command "mycli autocomplete script powershell"); .$PROFILE
   
     2) (Optional) If you want matching completions printed below the command line, run this cmdlet:
   
        Set-PSReadlineKeyHandler -Key Tab -Function MenuComplete
   
     3) Start using autocomplete:
   
        mycli <TAB>                  # Command completion
        mycli command --<TAB>        # Flag completion
   
       Every time you enter <TAB>, the autocomplete feature displays a list of commands (or flags if you type --), along with their summaries. Enter a letter and then <TAB> again to narrow down the list until you end up with the complete command that you want to execute.
   
    Enjoy!

Expected behavior

PowerShell 7 (pwsh) should be detected correctly regardless of admin privileges.

Environment (please complete the following information):

• OS: Windows 11
• PowerShell version: 7.5.4
• oclif/core version: 4.8.0

Additional context

PowerShell 7's own $ShellId variable correctly returns Microsoft.PowerShell, confirming it's a PowerShell environment. However, oclif's detection relies on process.title as seen by Node.js, which shows "pwsh" instead of something containing "powershell" when not running as admin. This means oclif's detection method is fundamentally misaligned with how PowerShell 7 identifies itself in non-admin mode.

[jfeingold35]

@khaled4vokalz , thanks for logging this. We'll make sure we can reproduce this, and then we'll prioritize it on our backlog appropriately.