Remove cache bar

To save space, you could remove the cache progress bar.
Instead, I think it would be enough to continue using color-coding based on time. And when the countdown reaches the end, it should start flashing to make it more visible.

Start by locating the cache progress bar and countdown rendering in the Shell statusline plugin. Remove the bar while preserving time-based color coding, add flashing when the countdown ends, and verify the resulting statusline behavior.

Written by the indexing model from the issue text.