Fix login failure after connection

Addresses an issue where login fails with a "Unexpected end of JSON input" error after a successful Supabase connection.

src/components/auth/LoginForm.tsx

@@ -4,7 +4,7 @@ import { Link } from "react-router-dom";
 import { Label } from "@/components/ui/label";
 import { Input } from "@/components/ui/input";
 import { Button } from "@/components/ui/button";
-import { ArrowRight, Mail, KeyRound, Eye, EyeOff } from "lucide-react";
+import { ArrowRight, Mail, KeyRound, Eye, EyeOff, AlertTriangle } from "lucide-react";
 
 interface LoginFormProps {
   email: string;
@@ -29,6 +29,11 @@ const LoginForm: React.FC<LoginFormProps> = ({
   loginError,
   handleLogin
 }) => {
+  // CORS 또는 JSON 관련 오류인지 확인
+  const isCorsOrJsonError = loginError && 
+    (loginError.includes('JSON') || loginError.includes('CORS') || 
+     loginError.includes('프록시') || loginError.includes('서버 응답'));
+
   return (
     <div className="neuro-flat p-8 mb-6">
       <form onSubmit={handleLogin}>
@@ -71,8 +76,21 @@ const LoginForm: React.FC<LoginFormProps> = ({
           </div>
           
           {loginError && (
-            <div className="p-3 bg-red-50 text-red-600 rounded-md text-sm">
-              <p>{loginError}</p>
+            <div className={`p-3 ${isCorsOrJsonError ? 'bg-amber-50 text-amber-800' : 'bg-red-50 text-red-600'} rounded-md text-sm`}>
+              <div className="flex items-start gap-2">
+                <AlertTriangle className="h-5 w-5 flex-shrink-0 mt-0.5 text-amber-500" />
+                <div>
+                  <p className="font-medium">{loginError}</p>
+                  
+                  {isCorsOrJsonError && (
+                    <ul className="mt-2 list-disc pl-5 text-xs space-y-1 text-amber-700">
+                      <li>설정 페이지에서 다른 CORS 프록시 유형을 시도해 보세요.</li>
+                      <li>HTTPS URL을 사용하는 Supabase 인스턴스로 변경해 보세요.</li>
+                      <li>네트워크 연결 상태를 확인하세요.</li>
+                    </ul>
+                  )}
+                </div>
+              </div>
             </div>
           )}