2.5.0

• In background. A session whose turn ended while a background agent it
  started (a review, a long check) is still at work now says so: the same
  turning arc in teal, "In background", and what the agent is in the rail's
  tooltip. Its Claude's prompt is free, so you can talk to it meanwhile.
• Background work is seen sooner and longer. An agent started just as the
  turn ended counts right away (it read Idle until it wrote again), and one
  waiting on a long run stays counted for an hour instead of 15 minutes.