Three fixes after hrrr-point-rs restarts on the first live drain:
1. Type mismatch (hard error): the `profile` column on `hrrr_profiles`
is `jsonb[]` (one element per pressure level), but the Rust worker
was binding a single jsonb array-of-objects cast as `::jsonb`. Every
insert failed with `column "profile" is of type jsonb[] but
expression is of type jsonb`. Switched to
`Vec<sqlx::types::Json<Value>>`, dropped the explicit `::jsonb`
cast, and enabled sqlx's `json` feature so the encoder maps the
array into `_jsonb` correctly.
2. Silent zero-inserts: four consecutive 2019-09-22 batches completed
with `profiles_inserted: 0` and no diagnostic. Most likely the
upstream archive doesn't keep cycles that old, but without a log
it looks identical to a snap-mismatch bug. Added a WARN when both
surface and pressure grids come back empty so fetch-miss vs.
projection-miss is distinguishable.
3. OOMKilled: the pod took four OOM restarts in ten minutes at 1 Gi.
A single CONUS decode holds the ~40 MB blob, the ~200 MB wgrib2
working set, AND the full 92k-cell merged map until all requested
points drain. 1 Gi has no headroom. Bumped to 2 Gi, matching the
rest of the per-container budgets in this namespace.