Dropdown menu needs scrollbar/modularization + double-click to open layout

Description: The layout selection dropdown becomes too long when many layouts exist, and it has no scrollbar or grouping. Items at the bottom are hard or impossible to reach. Also, selecting a layout currently requires a single click in the dropdown, but it would be more intuitive if double-clicking a layout opened it immediately.

Steps to reproduce:

  1. Go to the CMS and open the Layout Editor.

  2. Click the layout selection dropdown (top-left).

  3. Ensure many layouts exist so the dropdown grows past the screen height.

  4. Notice that there is no scrollbar, no grouping, and some options become hidden.

  5. Try double-clicking a layout, it only selects it but does not open it.

Possible Solutions:

  1. Add a vertical scrollbar (overflow-y: auto) to the dropdown.

  2. Or modularize/group menu options.

  3. Add double-click support so double-clicking a layout immediately opens it (design).