Update the change log

Author: alihcsumer

packages/pluggable-widgets-tools/CHANGELOG.md

@@ -6,6 +6,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ## [Unreleased]
 
+### Added
+
+-   We added a built-in Jest mock for the `mendix` module, so widgets that import runtime values from it (e.g. `ValueStatus`, `FormatterType`) in unit tests no longer fail with "This package should not be used in the runtime".
+
 ## [11.12.0] - 2026-06-30
 
 ### Changed