Remove on-premise Supabase test code

Remove code related to on-premise Supabase testing.

src/components/SyncSettings.tsx

@@ -2,7 +2,7 @@
 import React, { useState, useEffect } from 'react';
 import { Switch } from "@/components/ui/switch";
 import { Label } from "@/components/ui/label";
-import { CloudUpload, RefreshCw, Database } from "lucide-react";
+import { CloudUpload, RefreshCw } from "lucide-react";
 import { isSyncEnabled, setSyncEnabled, syncAllData, getLastSyncTime } from "@/utils/syncUtils";
 import { toast } from "@/hooks/useToast.wrapper";
 import { useAuth } from "@/contexts/auth";
@@ -139,18 +139,6 @@ const SyncSettings = () => {
           </div>
         </div>
       )}
-      
-      {/* 온프레미스 Supabase 설정 버튼 추가 */}
-      <div className="pt-4 border-t border-gray-200">
-        <Button
-          variant="outline"
-          onClick={() => navigate('/supabase-settings')}
-          className="w-full flex items-center justify-center gap-2"
-        >
-          <Database className="h-4 w-4" />
-          <span>온프레미스 Supabase 설정</span>
-        </Button>
-      </div>
     </div>
   );
 };