fix(wildlife): draw what arrived when one sighting source fails

An iNaturalist rejection discarded a successful Acartia reply, and the
antimeridian Promise.all lost both halves when one failed. Each box now
settles independently; the failed part is reported on
sources.inaturalist (error and failed boxes), the layer keeps that
area's last iNaturalist rows and shows DEGRADED with retry timing, and
the update fails outright only when every requested source failed.

docs/CURRENT-STATE.md

@@ -121,6 +121,10 @@ Provider 429 cooldown is shared; 5xx cooldown is resource-specific. Failed tiles
 retain good cells for at most one hour. Stale replies carry `X-Data-Stale` and
 known `Retry-After`. Failures keep filters and drawn rows, reporting DEGRADED
 with retry timing; logs exclude request URLs and upstream exception text.
+A partial failure still draws what arrived: a failed iNaturalist request, or
+one failed half of an antimeridian view, keeps a good Acartia reply and the
+other half, retains that area's last iNaturalist rows and reports DEGRADED.
+The update fails outright only when every requested source failed.
 
 `/api/acartia/sightings` adds Salish Sea marine mammals within 45.5–50.5° N,
 126–121° W, cached ten minutes and stale for at most 24 h. A valid empty