Squid 1.7.8 Bug fix: Fall back to Windows PowerShell when pwsh-Core not installed. ProcessLauncherFactory unconditionally defaulted to pwsh (PowerShell 7 Core) on Windows, but pwsh is OPTIONAL — Microsoft doesn't bundle it with the OS. Every stock Windows tentacle without PS7 installed crashed with Win32Exception (2) "system cannot find the file specified" the moment any PowerShell script dispatched (upgrade, deployment, health check). Fix: probe pwsh.exe availability and auto-fall-back to the always-present OS-bundled PowerShell.exe 5.1 when absent. Operator opt-in via SQUID_TENTACLE_USE_WINDOWS_POWERSHELL=true still wins over the probe.