Admins had logs and nothing else: client errors only reached the
browser console. An admin can now set a Sentry-protocol address (DSN)
for Bugsink, GlitchTip or Sentry under System > Monitoring, or with
`ERROR_REPORTING_DSN`, `ERROR_REPORTING_DSN_FILE`,
`ERROR_REPORTING_SAMPLE_RATE` and `ERROR_REPORTING_ENVIRONMENT`.
Bulwark Lite reads the same from `errorReporting` in policy.json.
Everything stays off while no address is set.
- browsers report errors from the error boundaries, window.onerror,
unhandled rejections and failed JMAP requests (method and error type
only), with route and JMAP method breadcrumbs and the chunks' debug IDs
- the server reports what Next hands to onRequestError and what routes
log with logger.error
- every report is scrubbed first: quoted text, addresses, URLs, file
names, tokens and the rest after the first line are removed, and the
server scrubs what browsers post to /api/errors again
- reports are deduplicated and rate-limited per session and process
- errors are counted per day for "errors today" on the admin page
- startup messages and audit entries go through the logger, so
`LOG_FORMAT=json` covers them