The skew-T commit (30c1018) doubled @pressure_levels from 13 to 25 so
new contact fetches would cover the full troposphere. That list is
also what PropagationGridWorker pulls per forecast hour, which
doubled the GRIB footprint (~57 MB compressed + 92k points × 25
levels × 3 vars decoded through wgrib2) and pushed prod pods over
their 4 Gi OOMKill threshold. Every chain died during f00 and the
map timeline never got beyond now and now+1h because the .ntms files
for f02-f18 were never written.
Split the constant:
* @profile_pressure_levels (25 levels, 1000-100 mb) drives the
per-contact HrrrClient.fetch_profile path so the skew-T plot
keeps its full-atmosphere trace.
* @grid_pressure_levels (13 levels, 1000-700 mb) drives the grid
hot path. That's the band SoundingParams.derive reads for
min_refractivity_gradient, and native hybrid-sigma data
(native_min_gradient) takes priority over the pressure-level
fallback anyway, so upper-air levels contribute nothing to
scoring — pure memory waste on this path.
build_profile/1 still iterates the full 25-level list; grid fetches
simply populate the 13 near-surface slots and skip the rest.
Makes HrrrClient.pressure_messages public with a :grid | :profile
variant so the split is testable from outside the module.