Function npmInvocation

src/upgrade/index.ts:640–645

(platform: NodeJS.Platform, npmArgs: string[])

 * `cmd.exe /d /s /c npm …` → works.)
 */
export function npmInvocation(platform: NodeJS.Platform, npmArgs: string[]): { cmd: string; args: string[] } {
  if (platform === 'win32') {
    return { cmd: 'cmd.exe', args: ['/d', '/s', '/c', ['npm', ...npmArgs].join(' ')] };
  }
  return { cmd: 'npm', args: npmArgs };
}

function upgradeNpm(
  method: Extract<InstallMethod, { kind: 'npm' }>,