Find the real cause of a Bugsnag error, with evidence

**Objective:** Work out what is causing the Bugsnag error `{error-id}` in project `{project-name}` and recommend a fix. Diagnose only. Do not change the error.

**Step 1: Read the error**

Call `bugsnag-get-error` with `error-id` set to `{error-id}`. Record the error class, message, severity, status, context, first and last seen dates, affected user count and `release-stages`.

**Step 2: Read the individual occurrences**

Call `bugsnag-get-event` with `error-id` set to `{error-id}` and `max-records` set to 25. Look across the events for:

* which `app-version` values it occurs in, and whether it is confined to recent ones
* whether it is `unhandled`, which means it reached the user
* the `file` and `context` the events share
* the `request-url` values, and whether they point at one route
* whether `received-at-date` shows it is still arriving or has stopped

**Step 3: Place it against releases**

Call `bugsnag-get-release` with `project-name` set to `{project-name}`. Find which release the error's first-seen date falls in, and whether `errors-introduced-count` for that release supports it being a regression from that build.

**Step 4: Report**

Give the most likely cause, the evidence for it, which app versions and release stages are affected, whether it is still occurring, and the recommended fix. State plainly how confident you are and what evidence would settle it.

**Rules & Guidelines:**

* Diagnose only. Do not call `bugsnag-fix-error`, `bugsnag-ignore-error`, `bugsnag-discard-error`, `bugsnag-update-error-severity`, `bugsnag-assign-error`, `bugsnag-create-error-issue` or `bugsnag-link-error-issue`.
* Do not stop at the first plausible cause. Say which causes you ruled out and on what evidence.
* Read the stack context from the events; the error record alone will not tell you where it happens.

**Validation:**

* If `{error-id}` returns nothing, say so and suggest running the triage prompt for `{project-name}` to find the right id.
* If the events all predate the last release, say the error may already be resolved and recommend confirming before any change.