Terminate the directly owned Windows command on cancellation and retain the
SQLite lock until child close. Record post-spawn errors without releasing
ownership early or leaving later error events unhandled.
Refs #4258
Co-authored-by: DeryFerd <deryferdikao125@gmail.com>
Use the existing pinned cross-spawn dependency at the command-spawn boundary instead of forcing every Windows executable and argument vector through cmd.exe. Preserve native executable arguments while retaining PATH/PATHEXT and command-shim support.
Validation: public runner argv and lock/cancellation tests passed on POSIX. Windows-only tests cover an executable path with spaces, bare node, npm, and the local turbo shim; native Windows execution remains unverified.
Fixes#2319
