PowerShell MCP server uses PowerShell 5.1 instead of PowerShell 7

Issue Description

The PowerShell MCP server built into Claude Code uses the legacy powershell.exe (PowerShell 5.1) instead of pwsh.exe (PowerShell 7).

Impact

• PowerShell 5.1 is the legacy Windows PowerShell that ships with Windows
• PowerShell 7+ is the modern, cross-platform version with significant improvements
• Users who have PowerShell 7 installed expect it to be used by default
• This violates the principle of least surprise for users who have migrated to PowerShell 7

Evidence

Testing mcp__powershell__execute-powershell shows:

• PSVersion: 5.1.26100.7019
• PSEdition: Desktop (legacy edition)
• Expected: PSVersion 7.x, PSEdition: Core

Reproduction

1. Install PowerShell 7 (pwsh.exe)
2. Use any PowerShell MCP tool via mcp__powershell__execute-powershell
3. Check $PSVersionTable
4. Observe PowerShell 5.1 is being used instead of PowerShell 7

Expected Behavior

Claude Code should use pwsh.exe (PowerShell 7) when available, falling back to powershell.exe only if PowerShell 7 is not installed.

Environment

• OS: Windows 11
• Claude Code: 2.0.37
• PowerShell 7: Installed at C:\Program Files\PowerShell\7\pwsh.exe
• PowerShell 5.1: C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe

Technical Details

The PowerShell executable path appears to be hardcoded in the Claude Code native binary (resources/native-binary/claude.exe) rather than being configurable.