* refactor: auto-review fixes and UI improvements
- Remove dead code and fix type assertion in getBranchDiff
- Tighten GitDiffBinaryResult type constraint
- Fix race condition in CombinedDiffViewer with generationRef
- Fix reference stability in setGitBranchCompareResult
- Extract LazySection component to fix max-lines lint
- Update filesystem IPC to match updated signatures
- Adjust file explorer item spacing and font size
* fix: correct test expectation for staged diff header label