* Land a turn's reply, completed footer, and tool summary in one frame
The stream handler closed turn liveness as soon as turn_completed arrived,
while the final reply waited in the frame-coalesced reducer queue. For one
commit the turn was finished with no reply: the footer vanished and the
timeline jumped twice, and tool turns folded into their summary later.
The viewed timeline owner now takes stream events whole: a turn boundary
commits the queued content before liveness changes. Running and completed
footers share one fixed content height so the phase switch moves nothing.
* Document the turn-boundary commit and stop racing the re-pin in the turn-open test
The turn-open test scrolled the received message into view with a
programmatic scroll, which leaves the chat following its end. Pressing
the turn summary swaps its icon, and that DOM change re-pins the chat to
the end between pointerdown and pointerup. The summary had moved 14 px,
which left the pointer 2 px inside the button; with the completed footer
now 2 px taller, it moved 16 px and the click landed on the reply below.
The message's fade and Show more are already on screen at the end, so
the test no longer scrolls.
Mohamed Boudra
a9bce9a18d