add line to release notes about durable session fix (#3126)

Author: sawka

docs/docs/releasenotes.mdx

@@ -27,6 +27,7 @@ Wave v0.14.4 introduces vertical tabs, upgrades to xterm.js v6, and includes a c
 - **macOS First Click** - Improved first-click handling on macOS (cancel the click but properly set block/WaveAI focus)
 - Deprecated legacy AI widget has been removed
 - [bugfix] Fixed focus bug for newly created blocks
+- [bugfix] Fixed an issue around starting a new durable session by splitting an old one
 - Electron upgraded to v41
 - Package updates and dependency upgrades