feat(editor): improve select perf (#15353)

maybe fix #12675


#### PR Dependency Tree


* **PR #15353** 👈

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**
- Improved block selection updates so selected states refresh reliably.
  - Corrected selected-block ordering and duplicate handling.
- Improved toolbar positioning accuracy and reduced unnecessary layout
recalculations.
  - Adjusted toolbar animation behavior for surface-based tools.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

blocksuite/affine/components/src/caption/captioned-block-component.ts

@@ -1,4 +1,5 @@
 import { ThemeProvider } from '@blocksuite/affine-shared/services';
+import { watch } from '@blocksuite/global/lit';
 import { BlockComponent, type BlockService } from '@blocksuite/std';
 import type { BlockModel } from '@blocksuite/store';
 import { html, nothing } from 'lit';
@@ -59,7 +60,7 @@ export class CaptionedBlockComponent<
         : nothing}
       ${this.selectedStyle === SelectedStyle.Background
         ? html`<affine-block-selection
-            .selected=${this.selected$.value}
+            .selected=${watch(this.selected$)}
           ></affine-block-selection>`
         : null}
       ${this.useZeroWidth && !this.store.readonly