Categorize space platforms list into collapsible groups

[outofgravity]

TL;DR

Allow space platforms to be organized into custom, collapsible categories.

What?

Add categories or folders to the space-platform list, such as:

Science
Cargo
Promethium
Inactive

Players could assign and manually sort platforms within each category. Categories could be collapsed to hide their platforms and keep the list compact.

Why?

Large saves can contain many platforms, making the current single list difficult to navigate. Collapsible categories would reduce clutter and make specific platforms faster to find.