Get configured smart-server pairs for RFQ or OTC:

• RFQ (default): GET /trading/v1/trade-pairs?server=smart_server.
• OTC: GET /trading/v1/trade-pairs?server=smart_server&tradeType=otc.

The response identifies data.tradeType and lists data.pairs, each with
asset, spendAsset, and supported sides:

• BUY: receive asset, spend spendAsset.
• SELL: spend asset, receive spendAsset.

Use the returned currency order and a listed side with
POST /trading/v1/{tradeType}/quote/smart-server. RFQ and OTC support differ;
do not assume a reverse pair or unlisted side is supported. Quote quantity
is in asset units; total is in spendAsset units. Swap the amount field
when reversing currency order to preserve its currency.

This list does not check live availability or reserve a quote. Server status,
provider support, liquidity, amount limits and account access can still
prevent a quote. Request a quote to check a specific trade.

server_1 through server_5 return legacy pair maps without RFQ/OTC
classification. Omit tradeType for these servers; supplying it returns
400. Server five currently returns an empty map.