Private-session payments in your reports, refundable, with real receipts

Money taken for private sessions and events now behaves like every other sale in Booking Bible:

- **Payments show up in your reports.** Card deposits and payments, and invoice payments (cash, bank transfer, Stripe pay-now) for private events are now recorded in your payment history — so they appear in the revenue report, the VAT report, sales by type, and payment methods, with the correct VAT share on each payment.

- **Clients get receipts.** Every settled private-event payment now sends the standard branded receipt to the booking's contact, with a proper receipt number.

- **Refunds work like everywhere else.** The booking's Payment tab lists each payment with a Refund button that opens the same refund dialog you use on client billing — including partial refunds and deposit-only refunds. Nothing is ever refunded automatically.

- **Cancellation fees follow your policy.** Cancelling a booking now applies the event type's own cancellation fee percentage and free-cancellation window (previously a fixed 50% was recorded regardless of your settings). The cancel dialog shows the resolved fee, what has been paid so far, and the suggested refund after the fee — and staff can adjust the fee for a specific cancellation. After cancelling a paid booking, a one-click "Refund X (keeps Y fee)" button drives the standard refund flow.