fix: Hide payment badge for performers with no payment obligation

Performers have nothing to pay unless they added a voluntary gift.
Only show PaymentBadge when registrationType is 'watcher' or giftAmount
> 0.

apps/web/src/routes/account.tsx

@@ -203,7 +203,13 @@ function AccountPage() {
 											</span>
 										)}
 									</div>
+									{/* Only show a payment badge when there's actually something to pay:
+								    watchers always have a drinkcard fee; anyone with a gift amount does too.
+								    Performers with no gift have nothing to pay → hide the badge. */}
+									{(registration.registrationType === "watcher" ||
+										(registration.giftAmount ?? 0) > 0) && (
 										<PaymentBadge status={registration.paymentStatus} />
+									)}
 								</div>
 
 								{/* Name */}