Clean up, reimplement native paper, and sign in screen.

app/index.tsx

@@ -1,5 +1,17 @@
+import { selectCurrentUser } from "@/redux/user/user.selectors";
 import { Redirect } from "expo-router";
+import { connect } from "react-redux";
+import { createStructuredSelector } from "reselect";
 
-export default function Index() {
-  return <Redirect href={`/jobs`} />;
+const mapStateToProps = createStructuredSelector({
+  currentUser: selectCurrentUser,
+});
+
+function Index({ currentUser }) {
+  if (currentUser.authorized) {
+    return <Redirect href="/" />;
+  }
+
+  return <Redirect href="/sign-in" />;
 }
+export default connect(mapStateToProps, null)(Index);