feat: use server-actions for authoring flow

This change actually makes the authoring flow work for
the most part by tying in emailing and more.

We have also done a number of quality of life updates to
simplify the codebase overall making it easier to continue
work on the refresh.

packages/email/index.ts

@@ -1 +1 @@
-export { render, renderAsync } from '@react-email/components';
+export {};