Persist welcome dialog visibility

The welcome dialog should remain visible until the user explicitly chooses to hide it.

src/components/onboarding/WelcomeDialog.tsx

@@ -1,5 +1,5 @@
 
-import React from "react";
+import React, { useState } from "react";
 import {
   Dialog,
   DialogContent,
@@ -11,15 +11,22 @@ import {
 import { Button } from "@/components/ui/button";
 import { Separator } from "@/components/ui/separator";
 import { ArrowRight, Wallet, PieChart, LineChart } from "lucide-react";
+import { Checkbox } from "@/components/ui/checkbox";
 
 interface WelcomeDialogProps {
   open: boolean;
-  onClose: () => void;
+  onClose: (dontShowAgain: boolean) => void;
 }
 
 const WelcomeDialog: React.FC<WelcomeDialogProps> = ({ open, onClose }) => {
+  const [dontShowAgain, setDontShowAgain] = useState(false);
+
+  const handleClose = () => {
+    onClose(dontShowAgain);
+  };
+
   return (
-    <Dialog open={open} onOpenChange={onClose}>
+    <Dialog open={open} onOpenChange={() => handleClose()}>
       <DialogContent className="sm:max-w-md">
         <DialogHeader>
           <DialogTitle className="text-center text-2xl text-neuro-income mb-2">
@@ -72,10 +79,24 @@ const WelcomeDialog: React.FC<WelcomeDialogProps> = ({ open, onClose }) => {
           </div>
         </div>
 
+        <div className="flex items-center space-x-2 mt-4">
+          <Checkbox 
+            id="dont-show-again" 
+            checked={dontShowAgain} 
+            onCheckedChange={(checked) => setDontShowAgain(checked === true)}
+          />
+          <label
+            htmlFor="dont-show-again"
+            className="text-sm font-medium leading-none peer-disabled:cursor-not-allowed peer-disabled:opacity-70"
+          >
+            더 이상 보지 않기
+          </label>
+        </div>
+
         <DialogFooter className="sm:justify-center">
           <Button 
             className="w-full sm:w-auto bg-neuro-income text-white hover:bg-neuro-income/90 focus:outline-none focus:ring-0"
-            onClick={onClose}
+            onClick={handleClose}
           >
             시작하기 <ArrowRight className="ml-2 h-4 w-4" />
           </Button>