Add auth and theme switcher

src/components/auth/SignInOutButton.tsx

@@ -0,0 +1,15 @@
+"use client"
+
+import { signIn, signOut } from "next-auth/react"
+
+export function SignInOutButton({ session }: { session: any }) {
+  return session ? (
+    <button onClick={() => signOut()} className="text-sm underline">
+      Sign out
+    </button>
+  ) : (
+    <button onClick={() => signIn("github")} className="text-sm underline">
+      Sign in with GitHub
+    </button>
+  )
+}