The Editor is a console-less GUI process. TerminalLauncher spawned cmd.exe
with UseShellExecute=false and CreateNoWindow=true and never redirected
stdin, so uvx.exe inherited an invalid stdin handle and died with
"The handle is invalid. (os error 6)" before the server could start.
Redirect stdin from NUL inside the cmd.exe payload so the child gets a
valid handle regardless of whether the Editor has a console.
Regression from #1201, shipped in v10.1.0.
Shutong Wu
b954897efd