The `stdin: 'ignore'` option was not working because spawn-rx expects
an Observable for its stdin option, not a string. This caused tsx watch
and vite dev server to hang waiting for stdin on Windows.
Use Node's native `stdio: ['ignore', 'pipe', 'pipe']` option instead,
which spawn-rx passes through correctly to child_process.spawn.
Fixes#550
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
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