Store the server's static loop-in confirmation-risk decision and the time it
was received. This lets recovered swaps reconstruct whether payment waiting had
already started and how much of the payment timeout remains.
Wire notification handling to persist accepted and rejected decisions before
caching and forwarding them. If the swap row is not present yet, the
notification is still cached so the per-swap waiter can replay and store the
decision later.
Recover accepted decisions by starting the payment deadline from the persisted
decision time, and recover rejected decisions by canceling the invoice and
failing the swap instead of waiting forever.
