Queue visibility in the UI

The current Pending runs count is misleading because it lumps together high-priority and low-priority (e.g. drift detection) runs without any distinction. Users can see a large pending number vs. a small worker count and panic.

• Surface run priority/ordering in the queue UI

• Show expected wait time or at least a priority-aware count something like: Workers: 6  Busy: 6  Pending: 7 (+ 183 low-priority tasks) as a quick win, with a long term goal of an AI-estimated wait time in minutes.