Node had no sibling for the Rust and Python `fetch_btcusdt`
data-generators — adding it closes the "fetch (data-gen)" cell for the
last remaining row of the cross-language example matrix where the
pattern makes sense.
* examples/node/fetch_btcusdt.js — uses Node 18+'s built-in global
`fetch` (no npm dependencies); same pagination logic as the Rust and
Python siblings (paginate backwards via `endTime`, drop the
in-progress bucket, sort and trim to the configured target). Applies
the same OHLC validity check the Rust `Candle::new` constructor
enforces so a malformed kline is skipped rather than written.
* JavaScript's `String(v)` already gives the shortest round-trip
representation and strips the `.0` suffix for whole-number floats, so
the CSV output is byte-for-byte identical to what the Rust and
Python fetchers produce on the same Binance snapshot. Verified by
running it and `git diff`-ing against the checked-in dataset: every
row older than the run is unchanged; only the most recent ~24 hours
drift because the market kept moving.
examples/README.md gains the new row.
kingchenc