OPTIONAL await — resolves on a terminal result, rejects on the timeout. Fire-and-forget rails may never resolve it; that is allowed.
Optionalopts: { timeoutMs?: number }Progress stream; returns an unsubscribe fn. Replays the latest update.
A terminal "failed" update carries the rejection in error (for swap rails
a SwapError whose isRefundable/pendingSwap drive recovery).
An in-flight payment. Observe it — its outcome may also arrive out-of-band (swap monitor / webhook) and surface as a tx in the wallet's history.