Add process.Child.Cwd, use it for cwd and remove cwd_dir field

The user must now explicitly choose between inheriting the current CWD, passing a path for the CWD, or passing a Dir for the CWD.
05346e123bRyan Liptak committed on 2/2/2026, 9:41:35 AMparent83abd73
13 files changedLine totals unavailable