- New RefundBookingTableAction on the booking list row and detail page,
refunding a Confirmed booking directly via RefundBookingAction — no need
to hunt up its Payment on the Refunds resource first.
- Payment::refundableBalance() extracted from RefundBookingAction's private
balance check so both refund forms can display and cap against it.
- RefundBookingAction::resolveRefundablePayment() made public for the same
reason (round-trip leg resolution reused by the UI).
- Both refund forms (ProcessRefundAction and the new booking action) gain a
"Full refund" toggle, on by default, which refunds the payment's whole
remaining balance without requiring a manually typed amount. Turning it
off reveals an amount field capped at the refundable balance.