Close BS-3182, #12736
#### PR Dependency Tree
* **PR #12787** 👈
This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)
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## Summary by CodeRabbit
- **Bug Fixes**
- Improved the behavior when deleting empty lines and merging blocks,
ensuring more accurate handling of block deletion and cursor focus in
various scenarios.
- **Tests**
- Added new end-to-end tests to verify correct deletion of lines in
edgeless text and paragraph blocks, including checks for block removal
and cursor position.
- Introduced a utility function to retrieve block IDs for testing
purposes.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
