Add Extensibility RNs

Author: quinntracy

content/en/docs/releasenotes/studio-pro/11/11.12.md

@@ -63,6 +63,9 @@ weight: 88
 - We fixed an issue where MCP connections could briefly disconnect and reconnect right after Studio Pro started up.
 - We fixed an issue where requests sent to MCP servers identified themselves with a generic browser user agent instead of Studio Pro.
 - We fixed an issue where Studio Pro could show a `No user is signed in` error while using an MCP server that requires Mendix Platform sign-in, while signed out.
+- We fixed a bug where the Extensions Overview page would not open if the user was not signed in.
+- We fixed a bug where reloading a Dev extension would cause a crash if extension tabs were still open.
+- We fixed an issue where progress dialogs did not behave like their C# counterpart. Canceling a step now waits for it to finish and return its result. To exit the step and return its result immediately on cancel, pass `resolveImmediatelyOnCancel` to `IDialogApi.showProgressDialog`.
 
 ### Known Issues