generateAuth function
Mint owner authority for the transaction sender. Owner authority is a
hot-potato Auth minted from the tx sender (ctx is implicit in a PTB)
and consumed by the very next account-loading call (load_account_mut
inside deposit_funds / withdraw_funds / mint / …). It resolves to
owner auth for whoever signs the transaction.
Implementation
TransactionResult Function(Transaction) generateAuth(PredictConfig cfg) =>
(tx) => account.generateAuth(config: toGeneratedConfig(cfg))(tx);