chore: bump crate to 0.2.1, update CHANGELOG

CHANGELOG.md

@@ -5,6 +5,15 @@ All notable changes to dagx 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] - 2025-10-07
+
+[View changes](https://github.com/swaits/dagx/compare/v0.2.0...v0.2.1)
+
+### Fixed
+
+- Fixed test execution on macOS by forcing `tokio::test` to use multi-threaded runtime
+  - Ensures tests pass consistently across all platforms
+
 ## [0.2.0] - 2025-10-08
 
 [View changes](https://github.com/swaits/dagx/compare/v0.1.0...v0.2.0)
@@ -144,5 +153,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - macOS (compatible)
 - Windows (compatible)
 
+[0.2.1]: https://github.com/swaits/dagx/tree/v0.2.1
 [0.2.0]: https://github.com/swaits/dagx/tree/v0.2.0
 [0.1.0]: https://github.com/swaits/dagx/tree/v0.1.0