Align session windows

### Feature summary

Custom alignment of session windows

### What problem are you trying to solve?

Currently I cannot monitor 3 sessions in parallel. I have to switch between windows.

### Proposed solution

I would LOVE a way to have sessions vertically aligned. So, for example, I have 3 active sessions... I can pull them all to the middle "stage" and align them 1 | 2 | 3 (vertically) and monitor each session. I'd also like to be able to switch between session focus, so if I see 1 needs input, I could do CTRL + 1 or something to jump to that session focus

### Workflow impact

Users-- you can watch as each agent works. I regularly read the "thinking" process and, currently, having sessions hidden when I'm viewing another session is annoying. Before the GH Copilot App, I would have 3 terminals in side-by-side, each with a GHCP CLI session running.

### Installation context

_No response_

### Additional context

_No response_