Contact detail page now renders an atmospheric profile section backed by
HRRR when available and ERA5 (reanalysis) otherwise, labeled with the
data source. When both sources are missing and HRRR is known-unavailable
(pre-2014 contacts), the Era5FetchWorker is enqueued so the month-tile
backfill gets triggered from a user visit.
Status page ERA5 progress previously computed "complete" as
(total_contacts - hrrr_unavailable_contacts), which treated every contact
with any HRRR status as ERA5-complete — inflating the bar to 76% while
era5_profiles had 0 rows. Replaced with a per-candidate EXISTS query
against era5_profiles using the same 0.15°/30-min tolerance
Weather.find_nearest_era5/3 uses at lookup time.