docs: update root CHANGELOG for v0.2.1 release

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

CHANGELOG.md

@@ -5,6 +5,15 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.2.1] - 2026-01-15
+
+### Changed
+
+- Fixed changeset configuration to remove non-existent @apps/* pattern
+- Added automated changeset-based version management and release workflow
+- Enhanced CI/CD workflows with GitHub Actions
+- Improved documentation for contributing and releasing
+
 ## [0.2.0] - 2026-01-15
 
 ### Added
@@ -38,5 +47,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Example applications in the examples directory
 - Complete documentation site with VitePress
 
+[0.2.1]: https://github.com/objectstack-ai/objectui/releases/tag/v0.2.1
 [0.2.0]: https://github.com/objectstack-ai/objectui/releases/tag/v0.2.0
 [0.1.0]: https://github.com/objectstack-ai/objectui/releases/tag/v0.1.0