fix: close tab overflow popover on window resize

When the window is resized while the tab overflow popover is open,
the popover would shift to the wrong position and no longer align
correctly. This change automatically closes the popover on window
resize, which is the standard UX pattern used by most UI libraries.

Fixes #1029

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

packages/dockview-core/src/dockview/components/popupService.ts

@@ -68,6 +68,9 @@ export class PopupService extends CompositeDisposable {
                     return; // clicked within popover
                 }
 
+                this.close();
+            }),
+            addDisposableListener(window, 'resize', () => {
                 this.close();
             })
         );