Update changelog

Author: code-asher

CHANGELOG.md

@@ -28,6 +28,15 @@ Code v1.122.0
 
 - Update to Code 1.122.0
 
+### Fixed
+
+- `--app-name` will now affect window titles within the editor (it is now used
+  as the value for `${appName}` in the title template).
+
+### Added
+
+- App name can now be set with the `CODE_SERVER_APP_NAME` environment variable.
+
 ## [4.121.0](https://github.com/coder/code-server/releases/tag/v4.121.0) - 2026-05-20
 
 Code v1.121.0