On-device UAT: the operator was timed out mid-read (120s), the chat turn
returned 'declined' while the dialog was still up, and their Approve then
hit a dead entry ('no such pending confirmation', 13:37:12 log). Nothing
executed — the gate failed safe — but the UX was a lie in both directions.
- CONFIRM_TIMEOUT 120s→300s: human-speed per T-13-51's own rubric.
- ContextBroker dispatches aiui:tool-confirm-expired when a pending action
vanishes node-side (poll) or the turn ends; Chat.vue closes the modal on
it. Same host-only CustomEvent discipline; iframe has no path to it.
- Two new tests; 21/21 green across toolConfirm + chatAiuiEmbed.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
