fix: fall back to cmd.exe when PowerShell unavailable on Windows (#11960)

[ChenXin-2009]

Description

Fixes #11960

On Windows,
un_terminal_command\ always uses \child_process.spawn('powershell.exe', ...)\ to run terminal commands. When PowerShell is unavailable due to corporate security policy (or any other reason), this fails with \spawn UNKNOWN.

Changes

• \core/tools/implementations/runTerminalCommand.ts: Added \isPowerShellAvailable()\ check that probes for \powershell.exe\ using \execFileSync. When not found, falls back to %COMSPEC%\ (typically \cmd.exe) with /C\ argument, which is always available on Windows.

All three spawn paths (streaming, non-streaming, background/detached) benefit from this fix since they all go through \getShellCommand().

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Summary by cubic

On Windows, fall back to cmd.exe when PowerShell is unavailable to avoid “spawn UNKNOWN” and keep terminal commands working in restricted environments.

• Bug Fixes
  • Added cached isPowerShellAvailable() using execFileSync to probe powershell.exe once, avoiding repeated 3s checks.
  • Updated getShellCommand() to use %COMSPEC% (defaults to cmd.exe) with /C when PowerShell is missing; affects streaming, non-streaming, and detached spawns.

^{Written for commit 89d3d31. Summary will update on new commits.}

[cubic-dev-ai]

1 issue found across 1 file

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