docs: move incorrectly placed changelog entry

Author: naveensingh

CHANGELOG.md

@@ -5,6 +5,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Fixed
+- Fixed an issue where existing files were overwritten when saving new files ([#131])
 
 ## [1.4.0] - 2025-10-29
 ### Changed