Option to disable Spaces bar

EDIT 07/14/2026: Implemented in my Element fork [Haven Desktop](https://github.com/Haven-Organization/haven-desktop)

### Your use case

When using a vertical monitor or using Element in a vertical window, the Spaces bar on the left can take up a lot of unnecessary space. There is a way to disable the communities bar, but not this new Spaces one.

There should be a way to hide the bar. Once disabled, Spaces would either need to be accessed some other way or have the bar re-enabled when there is a need to access them.

### Have you considered any alternatives?

Currently Spaces can be kept off and aren't used so for now I'm leaving it off but eventually this will be enabled for all.

### Additional context

_No response_