fix(editor): deactivate editor when selection out of editor (#13490)

Close
[AI-415](https://linear.app/affine-design/issue/AI-415/code-artifact-复制更好的支持code-block和插入正文)

#### PR Dependency Tree


* **PR #13490** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

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

* **Bug Fixes**
* Editor now deactivates when text selection moves outside the app,
preventing unintended interactions.
* Better handling when selection changes to external content, reducing
cases where the editor stayed active incorrectly.

* **Stability**
* Improved reliability around selection, focus, and visibility changes
to avoid accidental edits or actions.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->


#### PR Dependency Tree


* **PR #13490** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

blocksuite/framework/std/src/event/dispatcher.ts

@@ -226,6 +226,18 @@ export class UIEventDispatcher extends LifeCycleWatcher {
         this._setActive(false);
       }
     });
+    // When the selection is outside the host, the event dispatcher should be inactive
+    this.disposables.addFromEvent(document, 'selectionchange', () => {
+      const sel = document.getSelection();
+      if (!sel || sel.rangeCount === 0) return;
+      const { anchorNode, focusNode } = sel;
+      if (
+        (anchorNode && !this.host.contains(anchorNode)) ||
+        (focusNode && !this.host.contains(focusNode))
+      ) {
+        this._setActive(false);
+      }
+    });
   }
 
   private _buildEventScopeBySelection(name: EventName) {