v0.13.0 no turn ceiling, and a stop button that is always there

Removed. The turn ceiling. One instruction used to stop at twenty-five model turns and raise task did not finish within max_turns=25, which in practice ended long tasks that were going fine, one step before they might have answered, with the transcript at its largest and every step already paid for. It is removed rather than raised: there is no max_turns left to set.

Changed. The stop control is its own button instead of a mode of the send button. As a mode it disappeared as soon as anything was typed while the agent worked, which is where a person's hands are; it now follows the run, and queueing a follow-up still works beside it. With no ceiling this button is what ends a run that will not converge, so it has to be there when it is wanted.

Fixed. The model request now runs in a thread. It is a synchronous HTTP call and it sat on the event loop: measured at zero scheduler slices during a 300 ms call, so the stop route could not be served, no event reached the page, and the live pane did not repaint for as long as the model was thinking. Stopping is prompt now instead of waiting for the step in flight. A request already sent is still paid for and then dropped, which is said where it happens rather than promised away.

Also. Seven wiki pages described the cap, three of them resting advice on it; they now describe what actually bounds a run and say plainly that a stop only works while somebody is looking. And the CLI tests, which scrubbed provider variables but never the .env file the README tells people to write, no longer fail on any machine that has one.