Allow reducing size of the left column

Is your feature request related to a problem? Please describe. Vertical split at the "Status [1]" section is at 50% which is suboptimal in many cases. List of files is likely to take (much) less space compared to the diff.

Describe the solution you'd like Either resize it dynamically or make it user-configurable. Or, allow changing on the fly.

Describe alternatives you've considered Reposition screen from vertical to horizontal orientation or purchase a wider monitor.

Additional context