Distinguish text from prompts in KnownAiUseExamples

Some KnownAiUseExamples are simple texts, others are AI prompts. A simple checkbox on the model `is_prompt` should be enough to distinguish the two. Prompts should always be last in the list (both in the form and in the report), so adding an `order_by` would be good.

In the form, it would be nice to style prompts as such somehow, with `typewriter text` or by having the characters appear one after the other, as if someone's typing them. There are bound to be readily available solutions out there.

https://www.w3schools.com/howto/howto_js_typewriter.asp

Locate the KnownAiUseExamples model and the form and report entry points mentioned in the issue. Add a way to distinguish prompts from simple text, ensure prompts appear last in both views, and confirm the intended prompt styling before treating that optional presentation work as done.

Written by the indexing model from the issue text.