EDIT: PLEASE IGNORE (or someone can delete this)
I found how to remove articles from SmartSearch.

Is your feature request related to a problem? Please describe.

Having taken over an old website and updated it to J4x there are dozens of articles in various categories that need to be reassigned to other categories.

For example, a 'Latest News' category has articles going back to 2010. They have been unpublished and archived, but they are still showing up in SmartSearch results. There is no point removing 'Latest News' from the SmartSearch index as it is still a valid category with current articles.

Describe the solution you'd like

EITHER:

In the Article manager:

1. filter by the relevant category
2. tick/check the 'Check all items' box
3. click the '... Actions' button
4. select 'Change category' and then be presented with a list of categories to choose from.

OR:

Make it possible to filter SmartSearch by published/unpublished articles within a category and not all articles within a category.

In fact, I can see a use for both the above options

Additional context

None, really