Tabbed Forms

Tabs are now an official built-in layout.

Fast path:

1. define layout.kind = "tabs"
2. use mountTabsForm() for the built-in shell
3. switch to createFormView() only if the app needs custom chrome

const layout = {
  kind: "tabs",
  tabs: [
    {
      title: "Profile",
      children: [{ kind: "field", field: "name" }],
    },
    {
      title: "Details",
      children: [{ kind: "field", field: "email" }],
    },
  ],
};