Two wins on the hourly propagation pipeline:
1. Parallelize the chain. seed_chain was enqueuing only f00 and
each step self-enqueued f00+1, serializing ~2.5 min × 19
forecast hours into a ~48 min chain. Fan out all 19 jobs at
once — they're genuinely independent (different HRRR URLs,
different output files) — and let queue concurrency (2 slots
× 3 pods = 6 parallel workers) drop wall time to ~10 min.
Side effect: one permanently-failing step no longer takes out
the rest of the chain, so the rescue-chain logic I added last
commit becomes unnecessary. Removed.
The :final cleanup (retain_window + purge) used to run on the
fh=18 transition; with parallel execution we don't know which
step finishes last. Cleanup now relies on the existing
PropagationPruneWorker 15-min cron for time-based pruning.
Stale chain leftovers are already a minor concern with the
15-min prune; if file bloat becomes real, PruneWorker can
gain retain_window later.
2. Hoist band-invariant factors. score_time_of_day, score_sky,
score_wind, score_pressure depend on conditions only, not the
band — but composite_score was recomputing them 17 times per
point. Added Scorer.precompute_band_invariants/1, called once
per point before the bands loop; composite_score uses the
cached values when present and falls back to computing for
any caller that doesn't pre-warm (test harness, path
integrator). Saves ~30% of the scoring inner loop.
Graham McIntire
f122eedfa8