fix(editor): add comment entire to inner toolbar (#13304)

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[BS-3624](https://linear.app/affine-design/issue/BS-3624/page模式单选图片的时候希望有comment-按钮)




#### PR Dependency Tree


* **PR #13304** 👈

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

* **New Features**
* Added a comment button to the image and surface reference block
toolbars for easier commenting.

* **Refactor**
* Simplified array flattening operations across multiple components and
utilities by replacing `.map(...).flat()` with `.flatMap(...)`,
improving code readability and maintainability.

* **Bug Fixes**
* Improved comment creation logic to allow adding comments even when
selections exist.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/frontend/core/src/modules/collection/entities/collection.ts

@@ -66,7 +66,7 @@ export class Collection extends Entity<{ id: string }> {
               },
             ],
           })
-          .pipe(map(result => result.groups.map(group => group.items).flat()));
+          .pipe(map(result => result.groups.flatMap(group => group.items)));
       })
     );
   }