Updates CHANGELOG by describing new AI powered actions on a branch

(#4443, #4522)

Author: sergeibbb

CHANGELOG.md

@@ -18,6 +18,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/) and this p
   - Adds a new _upstream_ sub-command to the _branch_ Git Command Palette
 - Adds updated AI model support for GitLens' AI features
   - Adds GPT-5 family (GPT-5, GPT-5 Mini, GPT-5 Nano), and Claude 4.1 Opus models
+- Adds AI powered operations for a branch: "Recompose branch commits", "Recompose unpushed commits", "Explain Unpushed Changed". They are added to the _Commit Graph_ and views context menu for branches ([#4443](https://github.com/gitkraken/vscode-gitlens/issues/4443))
 - Add Azure DevOps Server integration support ([#4478](https://github.com/gitkraken/vscode-gitlens/issues/4478))
 - Adds ability to switch between open repositories on the _Visual History_
 - Adds _Visualize Repository History_ commands to the SCM menus