this change is aiming to fix the files still appearing in unstaged files even though it was just comitted. also the Pushing command would say synced! when done, this was just a filler from the fetching feature. this now has a Pushed! status, the same has been added to pulling
- Add comprehensive diff_viewer module with split-panel interface
- Replace simple `git diff` in `gg d` command with interactive viewer
- Implement two-mode navigation system:
* File list mode: navigate files with j/k, Enter to view
* Content mode: scroll diff content with j/k, ESC to return
- Support both tracked and untracked file diffs with proper handling
- Add color-coded diff display (green additions, red deletions)
- Include terminal raw mode handling for responsive keyboard input
- Add test files for diff viewer functionality
