Hello, I need the origin/baseURL for fetch/new URL.
I need it in server and client code.
What is the easiest setup to accomplish that in Next.js?

i.e.

// should be usable anywhere
const url = new URL('/api', process.env.ORIGIN)
// on `main` branch deployment `ORIGIN` would return `https://example.com`
// on `stagging` branch deployment `ORIGIN` would return `https://example.dev`
// on any other branch deployment `ORIGIN` would return process.env.VERCEL_URL
// on `npm run dev` would return dev url like `http://localhost:3000`