#385 fix (desktop): a couple more fixes to diff sidebar

Description

Related Issues

Type of Change

• [ x] Bug fix
• New feature
• Documentation
• Refactor
• Other (please describe):

Testing

Screenshots (if applicable)

Additional Notes

Summary by CodeRabbit

Release Notes

• Style
  • Refined sidebar layout with adjusted spacing and width constraints.
  • Optimized file item display with inline statistics and improved filename visibility through constrained widths.

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