Tell customers when the bug they reported is fixed

**Objective:** Close the loop on Bugsnag error `{error-id}` by updating the open Zendesk tickets it caused, using search text `{search-term}` (default: taken from the error's message), posting a public reply only if `{reply-publicly}` is true (default false: internal notes only).

**Step 1: Check the error is fixed**

Call `bugsnag-get-error` with error-id `{error-id}`. If nothing comes back, stop. If its status is not fixed, report its current status and stop; this prompt does not tell customers something is fixed when it is not.

**Step 2: Find the open tickets**

Using `{search-term}` or 1 to 3 short customer-facing fragments from the error's message and context, call `zendesk-get-ticket` with `subject.contains` set to each fragment and `created.from` set to the error's first-seen-date. Keep only tickets whose status is new, open, pending or hold.

For each, confirm with `zendesk-get-ticket-comment` that the conversation describes this failure. Discard the rest.

**Step 3: Confirm with the user**

List the confirmed tickets (ticket-id, subject, requester-email, status, assignee-name) and show the exact text you will post. If `{reply-publicly}` is true, draft a short, plain reply telling the requester the problem has been fixed and asking them to reply if they still see it; no error ids, class names or URLs in a public reply. Otherwise draft an internal note naming the error-id and that Bugsnag marks it fixed.

Ask the user to confirm the list and the text. They may remove tickets. Do not write anything until they confirm.

**Step 4: Update each confirmed ticket once**

For each ticket the user kept, call `zendesk-add-ticket-comment` once with `ticket-id`, `body` set to the agreed text, and `public` set to true only when `{reply-publicly}` is true, otherwise false.

**Step 5: Report**

A table: ticket-id, subject, comment added (public or internal), success or failure. Do not change any ticket's status; say that agents should solve the tickets once the customers confirm.

**Rules & Guidelines:**

* `bugsnag-get-error` is on the bugsnag server. `zendesk-get-ticket`, `zendesk-get-ticket-comment` and `zendesk-add-ticket-comment` are on the zendesk server.
* The only permitted write is `zendesk-add-ticket-comment`, once per confirmed ticket. Do NOT call `zendesk-update-ticket` (no status changes), `bugsnag-fix-error`, `bugsnag-open-error` or any other write tool.
* Never post a public reply unless `{reply-publicly}` is exactly true.

**Validation:**

* If no open ticket matches, report that there is nobody to notify and stop.
* If a comment fails, report it and continue with the remaining tickets; do not retry automatically.
* Pass dates as YYYY-MM-DD.