feat: runtime env

Support runtime environment variables using server components.

This will mean docker images can change env vars for runtime as required.

packages/lib/universal/use-base-url.ts

@@ -0,0 +1,20 @@
+import { useRuntimeEnv } from './runtime-env/client';
+
+/* eslint-disable turbo/no-undeclared-env-vars */
+export const useBaseUrl = () => {
+  const { NEXT_PUBLIC_WEBAPP_URL } = useRuntimeEnv();
+
+  if (typeof window !== 'undefined') {
+    return '';
+  }
+
+  if (process.env.VERCEL_URL) {
+    return `https://${process.env.VERCEL_URL}`;
+  }
+
+  if (NEXT_PUBLIC_WEBAPP_URL) {
+    return NEXT_PUBLIC_WEBAPP_URL;
+  }
+
+  return `http://localhost:${process.env.PORT ?? 3000}`;
+};