Follow-ups to the salvaged WSL-bridge gating (#66447):
- wsl-path-bridge.ts: discard wsl.exe stderr so the 'WSL is not installed'
banner can never leak into an attached console on WSL-less machines (#80184).
- scripts/desktop-update/windows.ps1: add an explorer.exe-mediated detached
relaunch rung between the WMI attempt and the tethered Start-Process
fallback. When Win32_Process.Create fails (observed ReturnValue 8), the
Desktop no longer re-attaches to the hand-off console, so its stdout stops
flooding the window and the console can close.