Add back to home button on auth page

Added a "Kembali ke Beranda" (Back to Home) button on the login/signup
page to allow users to navigate back to the home page without needing
to authenticate.

Changes:
- Imported Link and ArrowLeft icon from lucide-react
- Added button above the auth card that links to "/"
- Wrapped content in a space-y-4 container for proper spacing

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/pages/Auth.tsx

@@ -1,5 +1,5 @@
 import { useState, useEffect } from 'react';
-import { useNavigate } from 'react-router-dom';
+import { useNavigate, Link } from 'react-router-dom';
 import { useAuth } from '@/hooks/useAuth';
 import { Button } from '@/components/ui/button';
 import { Input } from '@/components/ui/input';
@@ -7,6 +7,7 @@ import { Label } from '@/components/ui/label';
 import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card';
 import { toast } from '@/hooks/use-toast';
 import { z } from 'zod';
+import { ArrowLeft } from 'lucide-react';
 
 const emailSchema = z.string().email('Invalid email address');
 const passwordSchema = z.string().min(6, 'Password must be at least 6 characters');
@@ -71,7 +72,16 @@ export default function Auth() {
 
   return (
     <div className="min-h-screen flex items-center justify-center bg-background p-4">
-      <Card className="w-full max-w-md border-2 border-border shadow-md">
+      <div className="w-full max-w-md space-y-4">
+        {/* Back to Home Button */}
+        <Link to="/">
+          <Button variant="ghost" className="gap-2">
+            <ArrowLeft className="w-4 h-4" />
+            Kembali ke Beranda
+          </Button>
+        </Link>
+
+        <Card className="border-2 border-border shadow-md">
           <CardHeader>
             <CardTitle className="text-2xl">{isLogin ? 'Login' : 'Sign Up'}</CardTitle>
             <CardDescription>
@@ -132,5 +142,6 @@ export default function Auth() {
           </CardContent>
         </Card>
       </div>
+    </div>
   );
 }