#### PR Dependency Tree
* **PR #13464**
* **PR #13465** 👈
* **PR #13471**
* **PR #13472**
* **PR #13473**
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 stacking order across canvas elements (shapes, connectors,
brush, highlighter), reducing unexpected overlap.
* Corrected z-index application for placeholders and fully rendered
elements to ensure consistent layering during edits.
* **Refactor**
* Centralized z-index handling for canvas elements to provide
predictable, uniform layering behavior across the app.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
This PR fixed that the block is missing in the selecte-all set after undo a dragging from canvas to note. Related to #12473
### Before
https://github.com/user-attachments/assets/828b4f48-689a-4975-bba6-f380f324de3c
### After
https://github.com/user-attachments/assets/9996c1ca-c3ea-415c-ab2b-359d826a1ffa
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **Bug Fixes**
- Improved handling of changes to child elements, ensuring more accurate updates when items are added or removed. This results in more reliable display and interaction with nested components.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
