- Created SideBySideDiffViewer component with unified and split-view modes
- Added view mode toggle to BatchDiffApproval component
- Integrated VSCode diff editor color variables for proper theming
- Added comprehensive test coverage for the new component
- Fixed vitest configuration to support React development mode for testing
The implementation provides:
- File navigation controls for multi-file operations
- Parallel columns showing original vs modified content
- Color coding for additions, deletions, and unchanged lines
- Summary view showing all affected files
- Toggle between traditional search/replace and modern side-by-side views
