Trim credit-at-booking comment to one line

Co-authored-by: anthropic/claude-opus-4-8

src/Booking/LessonBooker.php

@@ -196,13 +196,7 @@ class LessonBooker {
 				payerId: $payerId
 			);
 
-			// A scheduled lesson charged at booking — the extra lesson added to (or a
-			// cancelled one rebooked within) an already-billed month — skips the daily
-			// scan, so apply the payer's account credit here too. A cancellation credit
-			// then settles the rebooking instead of the family being charged twice for
-			// the same slot. A pending payment fully covered by credit is settled and
-			// its lesson confirmed; applyCredits is a no-op when the payer holds no
-			// balance.
+			// Apply any available credit while booking.
 			if ( $offering->isScheduledBilling() && null !== $payment && null !== $payment->id && Payment::STATUS_PENDING === $payment->status ) {
 				$this->payments->applyCredits( $payerId, [ $payment ] );
 				$payment = $this->payments->findPayment( (int) $payment->id ) ?? $payment;