Enabled Markdown Support in Private Message

It would be great if messages in FluentCommunity chat—such as threads at /portal/chat?thread_id=1485 — rendered Markdown properly.

At a minimum, support for links, bulleted/numbered lists, and spoilers would make conversations much easier to read. If large headings like H1 feel too disruptive for chat, those could be excluded while keeping the more practical formatting options enabled.

It would also be useful to support pasting images and audio directly from the clipboard.

• [markdown support example](https://imgur.com/e2n2Bn9)
• https://imgur.com/e2n2Bn9