Use Markdown in AI chat messages

[InAnYan]

Is your suggestion for improvement related to a problem? Please describe.

Currently, chat messages are formatted in a TextArea. This allows text to be selected, but the formatting is ugly. Markdown is a de-facto standard for chat LLMs.

Describe the solution you'd like

Use Markdown in AI chat messages with the ability to select and copy text.

Additional context

There is a long-standing problem with JavaFX: you cannot select Text or Label. Only text in TextField or TextArea can be selected. However, text in WebView can be selected, and it is already used in JabRef in entry preview!

Thus, you have 2 options:

1. Implement Markdown using Text or Labels and add a button Copy in the sidebar of a chat message (place where "Delete" button).
2. Implement Markdown using WebView.

Option 1 is, I think, easier to implement.

But Option 2 is tricky: at first glance it would solve the problem, but the question is -- performance overhead? WebView is like a tiny browser. Thus, a better option is to format the whole chat UI (only messages, not prompt) in a WebView.

Though the best way is to find a way to make Text or Label be selectable and copyable.