Red border on signup item

Updated the account menu to display a red border around the "Skapa konto" option by replacing the previous border classes with border-2 and border-red-600 for clearer emphasis.

X-Lovable-Edit-ID: edt-ebdcb8e1-4719-4314-9d31-88cde26235be

src/components/AccountMenu.tsx

@@ -60,7 +60,7 @@ const AccountMenu = () => {
             <>
               <DropdownMenuItem
                 onClick={() => handleOpenAuth("signup")}
-                className="cursor-pointer font-bold border border-primary rounded-md mx-1 my-1"
+                className="cursor-pointer font-bold border-2 border-red-600 rounded-md mx-1 my-1"
               >
                 Skapa konto
               </DropdownMenuItem>