Catch Bugsnag errors that nobody has logged in BugHerd

**Objective:** Find open errors in the Bugsnag project `{bugsnag-project}`, seen in the last `{lookback-days}` days (default 7), that hit pages of the website tracked by the BugHerd project `{project-name}` and have no BugHerd task.

How the two systems are linked: a BugHerd task created from a Bugsnag error carries "bugsnag:<error id>" in its external-id, and the Bugsnag error is linked to the task's admin-link with `bugsnag-link-error-issue`.

**Step 1: Read the open errors**

Call `bugsnag-get-error` with `project-name` set to `{bugsnag-project}`, `status` open, `last-seen.from` set to the start of the period and `max-records` 200. Order by users, highest first.

**Step 2: Keep the ones on the site**

Call `bugherd-get-projects` with `name.contains` set to `{project-name}`. If nothing matches, say so and stop. If several match, list their names and project-id values and ask which one; do not guess. Note its development-url and sites. For the top 30 errors, call `bugsnag-get-event` with `error-id` and `max-records` 5, and keep errors whose request-url is on the project's host. Match pages by URL: compare host and path, ignoring the scheme, a leading "www.", a trailing slash, the query string and the fragment.

**Step 3: Drop the logged ones**

For each kept error, call `bugherd-get-tasks` with `project-id` and `external-id` "bugsnag:<error id>". Drop errors with a task.

**Step 4: Report**

A table ordered by users: error-class, message, page, users, events, severity, first seen, error-url. Then the three to log first and why.

**Rules & Guidelines:**

* Tools named bugherd-... are on the bugherd MCP server; tools named bugsnag-... are on the bugsnag MCP server. If either set of tools is missing, say which server is not connected and stop.
* This prompt is read-only. Do not call any BugHerd write tool (`bugherd-add-task`, `bugherd-add-feedback`, `bugherd-update-task`, `bugherd-move-task`, `bugherd-add-comment`, `bugherd-add-attachment-from-url`, `bugherd-add-project`, `bugherd-update-project`, `bugherd-add-project-member`, `bugherd-add-guest-to-project`) or any Bugsnag write tool (`bugsnag-link-error-issue`, `bugsnag-create-error-issue`, `bugsnag-fix-error`, `bugsnag-open-error`, `bugsnag-ignore-error`, `bugsnag-discard-error`, `bugsnag-assign-error`, `bugsnag-update-error-severity`, `bugsnag-update-project`, `bugsnag-add-project`, `bugsnag-add-project-collaborator`). To log one, use `log-bugsnag-error-in-bugherd`.

**Validation:**

* If every error is already logged or none is on the site, say so.