fix(pos): keep the receipt printable after paying an order

Bug: confirming payment ran backToBoard() → clearSession(), wiping the cart's
activeOrderId, so the order vanished from the POS and the "print receipt" button
(which keys off activeOrderId) went dead — the only escape was a 4s toast.

Fix: capture the just-paid order id in local state (survives the session clear)
and show a persistent payment-success sheet with a "چاپ فاکتور" button so the
cashier can print/reprint the customer receipt, then "سفارش جدید" to continue.
Shared printReceiptById() backs both the in-order button and the success sheet.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

web/dashboard/src/components/pos2/pos2-screen.tsx

@@ -121,6 +121,8 @@ export function Pos2Screen() {
   const [busy, setBusy] = useState(false);
   const [payTarget, setPayTarget] = useState<Order | null>(null);
   const [payLoyalty, setPayLoyalty] = useState(0);
+  // Order just paid — kept after the cart is cleared so the receipt stays printable.
+  const [paidOrderId, setPaidOrderId] = useState<string | null>(null);
 
   const [online, setOnline] = useState(true);
   useEffect(() => {
@@ -287,13 +289,14 @@ export function Pos2Screen() {
         loyaltyPointsToRedeem: loyaltyRedeem > 0 ? loyaltyRedeem : undefined,
       });
       const paid = payments.reduce((s, p) => s + p.amount, 0);
-      const paidOrderId = payTarget.id;
-      notify.success(`پرداخت ${fmt(paid)} تومان ثبت شد`, {
-        action: { label: "چاپ فاکتور", onClick: () => void printReceipt(cafeId as string, paidOrderId) },
-      });
+      const justPaidOrderId = payTarget.id;
+      notify.success(`پرداخت ${fmt(paid)} تومان ثبت شد`);
       queryClient.invalidateQueries({ queryKey: ["tables-board", cafeId] });
       queryClient.invalidateQueries({ queryKey: ["orders-open", cafeId] });
       backToBoard();
+      // Keep the paid order id so the cashier can still print the receipt after
+      // the cart is cleared (the success sheet below uses it).
+      if (!isLocalOrder(justPaidOrderId)) setPaidOrderId(justPaidOrderId);
     } catch (e) {
       if (e instanceof ApiClientError && e.code.startsWith("POS_DEVICE")) {
         notify.error(posDeviceMsg(e));
@@ -307,14 +310,10 @@ export function Pos2Screen() {
     }
   };
 
-  // Print (or reprint) the customer receipt for the active, already-saved order.
-  const printActiveReceipt = async () => {
-    if (!activeOrderId || isLocalOrder(activeOrderId)) {
-      notify.error("ابتدا سفارش را ثبت کنید");
-      return;
-    }
+  // Print (or reprint) the customer receipt for a saved server order.
+  const printReceiptById = async (orderId: string) => {
     try {
-      await printReceipt(cafeId as string, activeOrderId);
+      await printReceipt(cafeId as string, orderId);
       notify.success("فاکتور برای چاپ ارسال شد");
     } catch (e) {
       const code = e instanceof ApiClientError ? e.code : "";
@@ -328,6 +327,14 @@ export function Pos2Screen() {
     }
   };
 
+  const printActiveReceipt = async () => {
+    if (!activeOrderId || isLocalOrder(activeOrderId)) {
+      notify.error("ابتدا سفارش را ثبت کنید");
+      return;
+    }
+    await printReceiptById(activeOrderId);
+  };
+
   // ── guards ───────────────────────────────────────────────────────────────
   if (!cafeId) {
     return (
@@ -613,6 +620,35 @@ export function Pos2Screen() {
           onConfirm={confirmPay}
         />
       )}
+
+      {paidOrderId && (
+        <div dir="rtl" className="fixed inset-0 z-[65] flex items-center justify-center p-4">
+          <div className="absolute inset-0 bg-black/50" onClick={() => setPaidOrderId(null)} />
+          <div className="relative w-full max-w-sm rounded-2xl bg-card p-6 text-center shadow-2xl">
+            <div className="mx-auto mb-3 flex size-14 items-center justify-center rounded-full bg-emerald-100 text-emerald-600">
+              <Check className="size-7" />
+            </div>
+            <p className="text-lg font-bold">پرداخت با موفقیت ثبت شد</p>
+            <p className="mt-1 text-sm text-muted-foreground">فاکتور مشتری را می‌توانید چاپ کنید</p>
+            <div className="mt-5 space-y-2">
+              <button
+                type="button"
+                onClick={() => void printReceiptById(paidOrderId)}
+                className="flex min-h-[52px] w-full items-center justify-center gap-2 rounded-xl bg-primary text-base font-bold text-primary-foreground transition-colors hover:bg-primary/90 active:scale-[0.99]"
+              >
+                <ReceiptText className="size-5" /> چاپ فاکتور
+              </button>
+              <button
+                type="button"
+                onClick={() => setPaidOrderId(null)}
+                className="flex min-h-[48px] w-full items-center justify-center rounded-xl bg-muted text-sm font-medium text-foreground hover:bg-accent"
+              >
+                سفارش جدید
+              </button>
+            </div>
+          </div>
+        </div>
+      )}
     </div>
   );
 }