[Feature Request] Add the ability to create a unique layout for snapping to the screen halves (left/right + top/bottom)

**Describe the feature you'd like**
Hi,
Currently, the extension supports quadrant tiling, but I’m not aware of the ability to snap windows to screen halves (not quarters). Maybe this feature already exists, but I couldn’t find it.
The layout I would like to use would be as follows:
- **Super + Left Arrow**: snap window to the left half of the screen
- **Super + Right Arrow**: snap window to the right half of the screen
- **Super + Up Arrow**: snap window to the top half of the screen (full width)
- **Super + Down Arrow**: snap window to the bottom half of the screen (full width)

Start by reviewing the existing quadrant-tiling implementation and how keyboard shortcuts are connected to layouts. Verify whether custom layouts already support screen halves, then define the four requested Super-plus-arrow actions and confirm that each places a window in the corresponding half across supported monitor setups.

Written by the indexing model from the issue text.