Gift cards and account balance now match the money received

Paid gift cards now appear in cash sales when the money is received, while
their revenue still remains deferred until the card is used. Refunds and repeat
payment notifications no longer make the sale appear twice.

Members can also add money directly to their own account balance without
sending themselves a gift card. They can choose how much of that balance to use
on an eligible purchase, and each venue's balance remains separate.

Balance holds now have a bounded lease. Booking Bible checks the payment
provider before releasing an expired hold, so a paid retry cannot lose its
credit and an abandoned checkout cannot lock the balance forever. A purchase
fully covered by gift/account value creates the pass and consumes both balances
in one database transaction.

Custom stored-value purchases use the amount range shown by Booking Bible, so a
venue website no longer needs its own different limit. The previous editable
gift-card limit in Membership Settings is now shown as an informational system
limit rather than a venue setting.

Top-up receipts now show the method that actually settled the charge (including
MobilePay), rather than the first payment method the checkout happened to offer.