feat(core): auto expand workbench sidebar when opening ai preview panel (#13058)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Added the ability to programmatically open and close the AI chat
preview panel, with improved control over its visibility and content.
* Introduced event notifications for preview panel open/close actions,
enabling responsive UI updates.

* **Enhancements**
* Automatically adjusts the sidebar width to a minimum value when the
preview panel is opened for optimal viewing.
* Improved synchronization between sidebar width and external changes,
ensuring a consistent user experience.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/frontend/core/src/modules/workbench/view/workbench-root.tsx

@@ -117,6 +117,7 @@ const WorkbenchSidebar = () => {
   const [resizing, setResizing] = useState(false);
 
   const workbench = useService(WorkbenchService).workbench;
+  const sidebarWidth = useLiveData(workbench.sidebarWidth$);
   const [width, setWidth] = useState(workbench.sidebarWidth$.value ?? 0);
 
   const views = useLiveData(workbench.views$);
@@ -152,6 +153,11 @@ const WorkbenchSidebar = () => {
     };
   }, []);
 
+  useEffect(() => {
+    if (resizing) return;
+    setWidth(sidebarWidth ?? 0);
+  }, [resizing, sidebarWidth]);
+
   return (
     <ResizePanel
       floating={floating}