Add trackpad gestures for space navigation (like Arc)

[jainnam-1993]

Currently switching between spaces requires clicking tabs or using keyboard shortcuts. Let's add support for trackpad gestures to make this more fluid.

Thinking:

Two-finger horizontal swipe to move between spaces
Smooth transition animations

This would make Zen feel more intuitive, similar to how Arc handles space navigation with trackpad gestures.
Should work across all platforms with trackpad support. Need to make sure it doesn't interfere with normal scrolling behavior within spaces.
Thoughts?

[Loskir]

It's already there, see this discussion: #827