Incorrect stack window is focused

## Description
The wrong stack window is focused in the following use case:
1. The command ```yabai -m window --stack ``` is used to stack the current window on top of another window.
2. A command such as ```yabai -m window --focus west``` is used to change focus to a different window that is not in the stack.
3. A command such as ```yabai -m window --focus east``` is used to change focus back to the stack.

**Expected result**
The window at the front of the stack is focused.

**Actual result**
The next window in the stack is focused instead of the one that is currently at the front.

**Additional notes**
The bug doesn't seem to occur if the windows change focus through mouse clicks or if the windows are stacked through the use of "mouse_drop_action".

Tested on yabai-v7.1.1

## Example

https://github.com/user-attachments/assets/61f58496-115b-483f-802e-cab951f0603a

The video uses the following command in the terminal:
```
sleep 1; yabai -m window --stack south; \
sleep 1; yabai -m window --focus west; \
sleep 1; yabai -m window --focus east;
```

Reproduce the issue using `yabai -m window --stack south`, then the `--focus west` and `--focus east` commands from the example. Trace the handling of stack and focus changes, comparing command-driven focus with mouse-driven focus. Done means returning focus to the stack selects the window currently at the front, rather than the next window.

Written by the indexing model from the issue text.