Order in topics per class

Nobody has claimed this yet.

### Feature request

I'm visualizing topics per class, but I experience two issues:

1. The order of the classes depend on which topics I visualize. And doesn't seem to follow a certain order. I want to always keep the same order and I would also like to specify a custom order myself (which should be kept the same whatever topics we are visualizing)
2. The width of the bars depend on which topics we are visualizing. I would like the width of the bar to always stay the same

Here is a video:

https://github.com/user-attachments/assets/bbe83d72-2b51-4a2d-9124-a928cd90f11d

### Motivation

Changing the order of the topics create unnecessary confusion.

Changing the bar widths is unnecessary.

### Your contribution

I would noe know how

The issue does not name files, tests, or an entry point. Start by locating the topic-per-class visualization implementation and review how class ordering and bar widths are calculated; done means the order can remain stable or be customized, and bar widths no longer change with the selected topics.

Written by the indexing model from the issue text.