Implement payment method placeholder

- Added placeholder card payment methods.
- Added a message indicating that the payment feature is not yet supported.
- Grayed out the "Add New Payment Method" button.

src/pages/PaymentMethods.tsx

@@ -4,6 +4,7 @@ import NavBar from '@/components/NavBar';
 import { ArrowLeft, CreditCard, PlusCircle } from 'lucide-react';
 import { useNavigate } from 'react-router-dom';
 import { Button } from '@/components/ui/button';
+import { useToast } from '@/hooks/use-toast';
 
 const PaymentMethodCard = ({ 
   type, 
@@ -46,6 +47,14 @@ const PaymentMethodCard = ({
 
 const PaymentMethods = () => {
   const navigate = useNavigate();
+  const { toast } = useToast();
+
+  const handleAddPayment = () => {
+    toast({
+      title: "알림",
+      description: "이 결제 기능은 아직 지원하지 않습니다.",
+    });
+  };
 
   return (
     <div className="min-h-screen bg-neuro-background pb-24">
@@ -85,20 +94,18 @@ const PaymentMethods = () => {
           />
         </div>
 
-        <div className="mb-8">
-          <h2 className="text-sm font-medium text-gray-500 mb-4 px-2">은행 계좌</h2>
-          
-          <PaymentMethodCard 
-            type="bank"
-            label="국민은행"
-            lastDigits="9876-54-321098"
-          />
+        {/* Notice */}
+        <div className="mb-8 p-4 bg-amber-50 rounded-md border border-amber-200">
+          <p className="text-amber-700 text-sm text-center">
+            이 결제 기능은 아직 지원하지 않습니다.
+          </p>
         </div>
 
         {/* Add Payment Method Button */}
         <div className="mt-8">
           <Button 
-            className="w-full bg-neuro-income hover:bg-neuro-income/90 text-white"
+            className="w-full bg-gray-400 hover:bg-gray-400/90 text-white cursor-not-allowed"
+            onClick={handleAddPayment}
           >
             <PlusCircle size={16} className="mr-2" />
             새 결제 수단 추가