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/widgets/toolbar/src/toolbar.ts

@@ -146,7 +146,16 @@ export class AffineToolbarWidget extends WidgetComponent {
   }
 
   setReferenceElementWithBlocks(blocks: BlockComponent[]) {
-    const getClientRects = () => blocks.map(e => e.getBoundingClientRect());
+    let cachedClientRects: DOMRect[] | null = null;
+    const getClientRects = () => {
+      if (!cachedClientRects) {
+        cachedClientRects = blocks.map(e => e.getBoundingClientRect());
+        requestAnimationFrame(() => {
+          cachedClientRects = null;
+        });
+      }
+      return cachedClientRects;
+    };
 
     this.referenceElement$.value = blocks.length
       ? () => ({