fix(studio): refresh builder top-bar name after a package rename (#2554)

The PackageSwitcher loaded the package list once (keyed on packageId) and
derived the top-bar name from it, but never listened for
`objectui:packages-changed` — which PackageFormDialog dispatches on
create/edit. So after renaming the current package via "edit", the header kept
showing the OLD name until a full page reload.

Re-fetch the switcher list on `objectui:packages-changed` so the top-bar name
reflects the rename immediately. Verified: dispatching the event triggers a
GET /api/v1/packages refetch, re-deriving the displayed name.

Co-authored-by: Jack Zhuang <277994282+os-zhuang@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: os-zhuang

packages/app-shell/src/views/studio-design/StudioDesignSurface.tsx

@@ -256,15 +256,24 @@ function PackageSwitcher({ packageId, tab }: { packageId: string; tab: string })
 
   React.useEffect(() => {
     let cancelled = false;
-    fetchPackages()
-      .then((parsed) => {
-        if (!cancelled) setPkgs(parsed);
-      })
-      .catch(() => {
-        /* leave null — switcher still works for navigation-free display */
-      });
+    const load = () => {
+      fetchPackages()
+        .then((parsed) => {
+          if (!cancelled) setPkgs(parsed);
+        })
+        .catch(() => {
+          /* leave null — switcher still works for navigation-free display */
+        });
+    };
+    load();
+    // Refresh the switcher list (and thus the top-bar package name) when a
+    // package is created or its manifest is edited elsewhere — PackageFormDialog
+    // dispatches `objectui:packages-changed` on create/edit. Without this the
+    // header showed the OLD name after a rename until a full page reload.
+    window.addEventListener('objectui:packages-changed', load);
     return () => {
       cancelled = true;
+      window.removeEventListener('objectui:packages-changed', load);
     };
   }, [packageId]);