- Introduced a new `ChangeMetadata` module to centralize change calculations, replacing the ad-hoc logic in `PatchTree`.
- Created `DiffUtil` to utilize the Myers diff algorithm for accurate line difference counts, aligning with Git's behavior.
- Updated `DomLabel` to display changes in a git-style format, including added and removed line counts.
- Added comprehensive tests for `DiffUtil` to ensure reliability and accuracy in various scenarios.
