fix: stabilize Toolbox navigation layout

CHANGELOG.md

@@ -3,6 +3,29 @@
 All notable changes to the independently versioned Toolbox SDK packages are
 recorded here. The packages currently share one release version.
 
+## 0.2.1 — 2026-07-23
+
+### Added
+
+- `ToolboxHeader.personalizeContent` for custom preferences inside the shared
+  controlled popover and `brandIconUrl` for a portal favicon with an inline
+  Toolbox cube fallback.
+- Accessible, mutually exclusive Personalize and Apps popovers that close on
+  Escape, outside interaction, and link selection.
+
+### Changed
+
+- The invariant top row now orders Personalize, Apps, source, and Help on the
+  left, keeps the text-only app identity geometrically centered, and fixes the
+  Toolbox brand/home block at the far right.
+- Personalize and Apps keep visible desktop labels, become compact icon controls
+  responsively without losing accessible names, and source and Help remain
+  present at every supported width.
+- `AppShell` now renders version, privacy, manifest actions, and legacy app
+  actions in a standard footer instead of changing the top-row geometry.
+- `iconUrl`, `leadingActions`, and `metadata` remain accepted for source
+  compatibility but are deprecated for the fixed header design.
+
 ## 0.2.0 — 2026-07-22
 
 ### Added