fix: production crash due to undefined import.meta.env by adding env utility and updating build script

src/utils/auth-client.ts

@@ -1,7 +1,8 @@
 import { createAuthClient } from "better-auth/react";
+import { VITE_PUBLIC_URL } from "./env";
 
 export const authClient = createAuthClient({
-	baseURL: import.meta.env.VITE_PUBLIC_URL || "http://localhost:3000",
+	baseURL: VITE_PUBLIC_URL,
 });
 
 export const { useSession, signIn, signOut, signUp, getSession } = authClient;