fix(web): screen readers hear which background thread finished, even with the sidebar collapsed#23839

Merge remote-tracking branch 'origin/main' into issue-watch/23811

Merge remote-tracking branch 'origin/main' into issue-watch/23811

fix(web): screen readers don't repeat an old status when a dialog closes

revert: background announcements speak even with in-app notifications on

fix(web): background announcements don't repeat in-app notification toasts

fix(web): Orca hears background thread announcements

fix(web): a subagent's request no longer borrows the parent's request id

fix(web): announce a repeat request and ignore a queued run cancelled mid-turn

fix(web): background announcements follow each run's ending and stay quiet while snoozed

fix(web): screen readers hear which background thread finished, even with the sidebar collapsed