Add :narr Oban queue to dev and runtime configs

Concurrency 6 in both dev and prod. NARR fetches are network-bound
(byte-range GETs to NCEI) so high concurrency is fine — same shape
as the iemre queue in dev. Required for NarrFetchWorker (added in
the previous commit) to actually pick up jobs.

config/dev.exs

@@ -82,6 +82,7 @@ config :microwaveprop, Oban,
     terrain: 4,
     commercial: 2,
     iemre: 10,
+    narr: 6,
     backfill_enqueue: 1
   ],
   plugins: [

config/runtime.exs

@@ -168,6 +168,7 @@ if config_env() == :prod do
       hrrr: 1,
       terrain: 3,
       iemre: 3,
+      narr: 6,
       # ERA5 queues are TEMPORARILY PAUSED while we diagnose the
       # zero-ingestion pipeline. Every poll in prod has been hitting
       # either CDS-rejected or long-running states; no `ERA5Batch: