quoteMint method
Exact pre-trade quote: dry-runs the caller's own mint (same tx as
tx.mint) and decodes the receipt. Requires a funded account; throws
the same typed errors the real trade would — quote doubles as preflight.
Implementation
Future<MintQuote> quoteMint(String owner, MarketDescriptor m,
{required num quantity}) async {
final tx = await _c._buildMint(owner, m, MintOptions(quantity: quantity));
return _c._quoteMintTransaction(owner, tx);
}