feat: add shared Toolbox header and themes

CHANGELOG.md

@@ -1,5 +1,19 @@
 # Changelog
 
+## 0.4.0
+
+### Added
+
+- Added the unified Toolbox top bar with a centered app title, standard Help and Gitea source controls, Personalize, and Apps switching.
+- Added persistent System, Light, and Dark appearance choices shared with the Toolbox Portal.
+- Added a real dark CodeMirror configuration with dark editor surfaces, gutters, active lines, and syntax highlighting.
+
+### Changed
+
+- Upgraded Toolbox Contract, React Shell, and Testkit dependencies to 0.2.0.
+- Replaced the app-specific Help and Source actions with the shared shell controls and manifest repository fallback.
+- Converted workbench controls, cards, diagnostics, dialogs, tables, and editor chrome to semantic theme variables.
+
 ## 0.3.2
 
 ### Added