process.stdout.write() is async when stdout is a pipe. The
immediate process.exit(0) tears down the process before the
downstream reader (jq, python3, etc) consumes the buffer,
producing truncated JSON.
Replace with fs.writeSync(1, data) which blocks until the
kernel pipe buffer accepts the bytes, and drop process.exit(0)
on the success path so the event loop drains naturally.
Fixes#1275
Related: #493 (addressed >50KB case, this fixes <50KB)
045eabbbf9