feat: add auth

app/auth.tsx

@@ -0,0 +1,16 @@
+import { Button, View } from "react-native";
+import { authClient } from "@/lib/auth-client";
+
+export default function Auth() {
+  const onLogin = () => {
+    authClient.signIn.oauth2({
+      providerId: "koon-family",
+    });
+  };
+
+  return (
+    <View>
+      <Button onPress={onLogin} title="Login with Koon Family" />
+    </View>
+  )
+}