add download keys button to onboarding process

src/app/auth/components/user.tsx

@@ -24,7 +24,7 @@ export function User({ pubkey, fallback }: { pubkey: string; fallback?: string }
     <div className="flex items-center gap-2">
       <div className="relative h-10 w-10 shrink rounded-md">
         <Image
-          src={user.picture || user.image}
+          src={user?.picture || user?.image}
           fallback={DEFAULT_AVATAR}
           alt={pubkey}
           className="h-10 w-10 rounded-md object-cover"
@@ -32,10 +32,10 @@ export function User({ pubkey, fallback }: { pubkey: string; fallback?: string }
       </div>
       <div className="flex w-full flex-1 flex-col items-start text-start">
         <span className="truncate font-medium leading-tight text-zinc-100">
-          {user.name || user.displayName || user.display_name}
+          {user?.name || user?.displayName || user?.display_name}
         </span>
         <span className="text-base leading-tight text-zinc-400">
-          {user.nip05?.toLowerCase() || shortenKey(pubkey)}
+          {user?.nip05?.toLowerCase() || shortenKey(pubkey)}
         </span>
       </div>
     </div>