fix· Linear
@mentions on a task Sinatra is already on are handled once, in their own session
When you @mention Sinatra on a Linear issue it already has a task for, your comment is the message it acts on, and the reply comes in the session Linear opened for it.
Linear opens a new agent session for every @mention, and three things went wrong with it. On an idle task, that session could arrive without your comment, so nothing ran. A reply under one of Sinatra's comments that also @mentioned it was handled twice. And while the agent was working, the mention could be folded into the running turn instead of answered where you asked. Now, if Sinatra is busy, the new session says right away "Finishing what I'm working on first, then I'll pick this up here." and your message runs as the next turn.
#1578, #1579, #1580