In Data Views, resizing results view and hiding the form leaves it collapsed

[grantfitzsimmons]

Describe the bug
Resizing the results view in Data Views makes Specify remember its width, but disabling the form view does not automatically force it to occupy the full width of the window.

To Reproduce
Steps to reproduce the behavior:

1. Resize the results view to be narrower or larger
2. Click on the multi-pane icon to hide the form view
3. See that the results view is not taking up the full width of the screen automatically

Screen.Recording.2026-10-02.at.10.35.57.AM.mov