createProcessInspector now returns a WindowsProcessInspector on win32
instead of throwing: Toolhelp32 tree enumeration with GetProcessTimes
start identities, the shell pid as a pseudo foreground group, taskkill
tree signalling, and inspector-verified Windows teardown (node-pty
signal kills throw on Windows, and externally taskkilled shells may
never fire its exit notification, so the handle settles \done\ from the
verified absence). subprocess-local and pty-local suites now run on
Windows with platform gates; the koffi-backed inspector joins the
windows-only coverage exclusions on Linux and is fully covered by the
windows-native lane.
Also flips vitest.config so subprocess-local and pty-local sources are
coverage-required on win32, and adapts the spawn/terminal suites to run
natively there (node-translated shell commands, injected POSIX group
paths, taskkill signal semantics).
