chore: update changelog

Author: AlCalzone

README.md

@@ -157,6 +157,9 @@ const json = db.toJSON();
 	Placeholder for next release:
 	### __WORK IN PROGRESS__
 -->
+### __WORK IN PROGRESS__
+* Fixes an issue where the application could run out of memory if a custom serializer threw an error during the automatic compression
+
 ### 4.0.0 (2025-10-07)
 * BREAKING: Drop support for Node.js versions older than v20
 * BREAKING: Removed `exportJson` method in favor of `toJSON`