Per-contact Oban worker that fetches one NARR profile via
NarrClient.fetch_profile_at/2 and inserts it into era5_profiles.
Replaces Era5FetchWorker for pre-2014 contacts. Unlike the ERA5
router, NARR fetches are per-point so this worker does the fetch
+ insert directly — no downstream batch worker, no routing.
Args shape matches Era5FetchWorker: %{"lat", "lon", "valid_time"}.
Lat/lon get snapped to 0.25° (same dedup granularity as ERA5).
valid_time MUST already be on a 3-hourly NARR analysis slot
(00/03/06/09/12/15/18/21 UTC on the hour) — the worker raises
ArgumentError via NarrClient.url_for/1 otherwise. Caller-side
snapping (in ContactWeatherEnqueueWorker) lands in the next task.
Existence check tightened to ±15 minutes (vs ERA5's ±30) since NARR
is exact 3-hourly. On error, logs a warning and returns {:error,
reason} so Oban retries with backoff (max_attempts: 3).
The :narr Oban queue config and the ContactWeatherEnqueueWorker
swap are deliberately NOT touched in this commit — those are the
next two tasks of the plan.
Graham McIntire
7c33af7278