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/runtime-env/server.tsx

@@ -0,0 +1,29 @@
+'use server';
+
+import React from 'react';
+
+import { RuntimeEnvClientProvider } from './client';
+import { PublicEnv } from './types';
+
+export type RuntimeEnvProviderProps = {
+  children: React.ReactNode;
+};
+
+export const RuntimeEnvProvider = ({ children }: RuntimeEnvProviderProps) => {
+  // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
+  const publicEnv = Object.entries(process.env)
+    .filter(([key]) => key.startsWith('NEXT_PUBLIC_'))
+    .reduce((acc, [key, value]) => ({ ...acc, [key]: value }), {}) as PublicEnv;
+
+  return (
+    <RuntimeEnvClientProvider value={publicEnv}>
+      {children}
+
+      <script
+        dangerouslySetInnerHTML={{
+          __html: `window.__unstable_runtimeEnv = ${JSON.stringify(publicEnv)}`,
+        }}
+      />
+    </RuntimeEnvClientProvider>
+  );
+};