fix: stabilize Toolbox navigation layout

README.md

@@ -5,7 +5,7 @@ tools. An app always works by itself. When it receives a trusted same-origin
 catalog URL, the same app gains a toolbox home link and an app switcher without
 becoming coupled to a portal or client-side router.
 
-Version `0.2.0` contains three publish-ready packages:
+Version `0.2.1` contains three publish-ready packages:
 
 - `@add-ideas/toolbox-contract` — types, strict v1 runtime parsing, context
   discovery/loading, resolved URLs, and contextual link helpers.
@@ -167,13 +167,26 @@ import "@add-ideas/toolbox-shell-react/styles.css";
 </AppShell>;
 ```
 
-The shell always renders a centered app identity, version, derived privacy
-facts, standard Help and source controls, Personalize, Apps, manifest actions,
-and legacy `appActions`. With valid context it additionally renders the catalog
-brand/home and available app destinations. Destinations are ordinary links, so
-switching performs full-page navigation. On missing, cross-origin, invalid, or
-unavailable context the shell quietly remains usable in standalone mode;
-`onContextError` is optional observability.
+The shell's fixed top row renders Personalize, Apps, source, and Help controls
+in that order, a geometrically centered text identity, and the Toolbox
+brand/home at the far right. Personalize and Apps have labeled desktop controls
+and retain their accessible names when compact. The mutually exclusive popovers
+close on Escape, outside interaction, and link selection.
+
+`AppShell` moves version, derived privacy facts, manifest actions, and legacy
+`appActions` into its standard footer, keeping the top row stable in connected
+and standalone modes. With valid context it supplies the catalog home, favicon,
+and available app destinations. Destinations are ordinary links, so switching
+performs full-page navigation. On missing, cross-origin, invalid, or unavailable
+context the shell quietly remains usable in standalone mode; `onContextError` is
+optional observability.
+
+For a custom portal-style header, `ToolboxHeader` accepts `personalizeContent`
+for content hosted inside the shared controlled popover and `brandIconUrl` for
+the Toolbox mark. `onPersonalize` remains available for callback-only
+integrations. The deprecated `iconUrl`, `leadingActions`, and `metadata` props
+are retained for source compatibility; the centered app icon is intentionally no
+longer rendered.
 
 CSS custom properties prefixed with `--toolbox-` are the v1 theme surface. The
 user's `light`, `dark`, or `system` preference is shared with same-origin apps