feat(admin): show payment date/time and recorder on session payments

Each recorded payment row (PaymentStep + DetailsStep) now shows the payment
date+time (paid_at, Jalali via formatDateTime, falling back to created_at) and
the user who recorded it (created_by_name) beneath the method/amount line. Both
fields were already in the API payload. Add created_at to SessionPaymentEntry.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

assets/admin/components/SessionServiceCard.tsx

@@ -7,6 +7,7 @@ export interface SessionPaymentEntry {
   method: string;
   amount_rials: number;
   paid_at?: number;
+  created_at?: number;
   created_by_name?: string | null;
 }