New Bubble for AI Assistant

We added a new bubble that makes it easier to call up the AI Assistant.

The AI Assistant is incredibly useful for answering questions about files, summarizing RSS feeds, and probably a lot of other things we haven't even considered. However, sometimes it was a bit hidden in the options.

We added a new blue bubble to make the AI Assistant easily accessible. Click the bubble to see options, whether it's from the left sidebar, with a file open, or when you've marked some text.