Bug: aborted daemon extension UI requests remain clickable and return Unknown extension UI request

[tamikomssi]

Problem

When a daemon extension UI dialog is aborted or times out after a competing decision (for example, Slack consent wins), the daemon removes the pending request but does not notify the connected interactive client. The terminal keeps the stale dialog. A later click sends extension_ui_response for the retired ID and receives Unknown extension UI request.

Reproduction

An executable regression covers: daemon emits dialog -> request aborts -> daemon request is removed -> interactive client still holds the exact ID -> late click attempts a response. On current main (97b994c) it makes one stale response call and surfaces the unknown-request error.

Proposed fix

Add a schema-revision-17, capability-gated extension_ui_cancelled outbound event. On actual pending-request cleanup, the daemon emits { activeSessionId, id }; only clients that advertise extension_ui_cancellation receive it; the agent connection forwards it within the active-session guard; the interactive client retires only that exact ID. Unknown cancellation IDs are no-ops. Unknown, duplicate, wrong-session, and legacy response handling remains fail-closed. A normal valid response is tested to emit no cancellation.

Tested fork commit: tamikomssi/prime-agent@c299890
Branch: https://github.com/tamikomssi/prime-agent/tree/fix/extension-ui-cancel-correlation

Verification: npm run check passes; five touched suites pass (429 tests); focused Claude Opus 5 security review returned PASS with no blocking findings. Broader suite retains unrelated environment/fixture failures outside the changed suites.

May I submit this as a pull request?

[tamikomssi]

Follow-up from a real isolated source-built daemon/client canary: the first patch (c299890) still failed in the supervisor/session-worker topology because the supervisor did not propagate extension_ui_cancellation to the worker. It also lacked per-client filtering on the supervisor outbound path.

Corrected head: tamikomssi/prime-agent@62659fe. It now propagates the capability to the worker when an attached UI client negotiated it, filters cancellation per attached client, and aborts the exact local dialog controller so the TUI visibly dismisses select/confirm/input/editor dialogs.

Fresh run-scoped canary evidence: capable client received the exact request and exact cancellation; /timed-signal auto-dismissed; late Enter produced no response or unknown-request error; legacy extension_ui-only client received no cancellation; deliberately unknown response remained rejected in the daemon log. Six touched suites pass (508 tests), npm run check passes, and the temporary canary socket/config/session store was removed. Fork draft PR #2 now points to the corrected head.