Dock: Add support for resizing to multiple rows

Nobody has claimed this yet.

### Description of the new feature / enhancement

Adding a dock seems like a very useful feature, especially considering the upcoming customization options. Here are some suggestions that, in my opinion, could enhance the dock experience and its integration with Windows:
- Ability to customize the dock’s size or thickness.
At the moment, the dock has a height similar to the taskbar, which can feel visually intrusive. Allowing users to adjust its thickness would make it more discreet and adaptable to different screen setups.
- Visibility across multiple monitors.
I use three monitors, and it feels inconsistent that the dock only appears on one of them. The visual experience would be much more cohesive if it could be displayed on all available monitors.

### Scenario when this would be used?

This feature would be used in scenarios where users want a more personalized and less intrusive experience. The ability to adjust the dock’s thickness allows it to adapt to different screen sizes or visual preferences, while having it visible across all monitors improves the ergonomics and consistency of the workspace.

### Supporting information

_No response_

No implementation files, tests, or entry points are named. Clarify whether the scope is dock thickness, multi-monitor visibility, or both, then locate the dock implementation and define completion as the selected behavior working consistently across the requested monitor and sizing scenarios.

Written by the indexing model from the issue text.