Pets often end up outside the border when resizing the panel

[Penrosian]

Describe the bug
When you resize the border, they can often end up outside of the border. If you make the panel smaller and cover up the pet, the pet just stays outside the border until it walks back in, and (assuming this is how the extension works) if the pet decides to walk to a point and then you decrease the size of the panel enough that that point is outside the border, the pet will still walk to that point.

Screenshots
This pet is only halfway past the border so that you can see that it is past the border, but most of the time they end up farther out.

Additional context
Could probably be fixed by just moving the pet back to the left if the pet ends up outside the panel, and maybe making the pet stop moving if the point it's trying to move to is outside the panel.