Post-2014 contacts with hrrr_status=:unavailable were being dispatched to
NARR, which 404s because NCEI's archive ends 2014-10-02. 14K of the 14.3K
candidates in prod are post-2014 — these are HRRR's responsibility.
- NarrClient.in_coverage?/1 returns true only inside 1979-01-01 → 2014-10-02
- narr_jobs_for_contact and maybe_enqueue_narr (contact_live) bail out of
coverage returning []
- BackfillEnqueueWorker.type_filter scopes :narr to qso_timestamp <
coverage_end so the cron doesn't keep picking post-2014 candidates