Make the meaning of compute server blue dots clear

[novoselt]

I don't know how to reproduce it, but the behaviour in a project without any compute servers created in it was unclear and probably some changes can be made to improve the appearance. What I saw were "spinning blue dots to the right of AI button" in all 3 frames of a markdown file with an open chat. Suggestions (which I hope are easy):

• add a tooltip explaining what it is
• make is spin on top of the yellow server button, in which case it would be clear that it is related somehow to the servers