Stop bundling Compound, let the host supply it

component/index.tsx

@@ -17,19 +17,25 @@ Please see LICENSE in the repository root for full details.
  * host instead, or is confined to the container it is mounted in.
  */
 
-// The design tokens, fonts and element defaults every Element Call stylesheet
+// The element defaults and custom properties every Element Call stylesheet
 // builds on. Written for a page, they speak of `html`, `body` and bare
 // elements; the component build confines them, and every other stylesheet in
 // this bundle, to the root element below (see build/scopeStylesToRoot.ts), so
 // that the host's document is left as it was.
 //
+// Compound is not in here. The component uses the host's copy of it (a peer
+// dependency, left external by the build), and the host loads Compound's
+// stylesheet, design tokens and fonts along with it: what Compound floats into
+// the host's body — tooltips, menus — is then styled by the same stylesheet as
+// everything else there, and Element Call's root takes the tokens and fonts of
+// the theme class it carries, as any element on the host's page would.
+//
 // Where these land relative to the component stylesheets is the bundler's
 // choice — the standalone app puts them first, this build puts them in the
 // middle — so nothing in base.css may depend on winning or losing against a
 // component's own rules at equal specificity. It currently does not: what it
 // declares unlayered is custom properties on Element Call's root, which
-// components inherit rather than compete with, and everything from Compound
-// sits in a `@layer`, which loses to unlayered rules either way.
+// components inherit rather than compete with.
 import "../src/base.css";
 
 import {
@@ -57,7 +63,6 @@ import { ErrorPage } from "../src/FullScreenView";
 import { ClientProvider } from "../src/ClientContext";
 import { HostBridgeProvider } from "../src/HostBridge";
 import { RootElementProvider, useRootElement } from "../src/RootElementContext";
-import { PortalRoot } from "./PortalRoot";
 import {
   configurationForIntent,
   componentProperties,
@@ -232,7 +237,9 @@ export const ElementCall: FC<ElementCallProps> = ({
         <UrlParamsProvider value={params}>
           <div ref={setContainer} className={styles.root}>
             {ready && (
-              <PortalRoot root={container}>
+              // Stands in for the standalone page's `#root`: see `.content`
+              // in ElementCall.module.css
+              <div className={styles.content}>
                 <RootElementProvider value={container}>
                   {/* Whatever goes wrong in here is shown in here. Left to
                   propagate, an error would unmount the host's own tree. */}
@@ -261,7 +268,7 @@ export const ElementCall: FC<ElementCallProps> = ({
                     </Decoration>
                   </ErrorBoundary>
                 </RootElementProvider>
-              </PortalRoot>
+              </div>
             )}
           </div>
         </UrlParamsProvider>