Pre-existing CI failure (`tests/scorer_golden.rs`) — the Rust scorer
was still on the pre-recalibration weight vector, while the Elixir
side picked up new gradient-descent-fit weights in f98ee153.
- Update `DEFAULT_WEIGHTS` in band_config.rs to match the new Elixir
values (humidity 0.1262, time_of_day 0.0380, td_depression 0.1010,
refractivity 0.0986, sky 0.0841, season 0.1134, wind 0.0841,
rain 0.1431, pressure 0.0967, pwat 0.1147).
- Loosen the sum-to-one tolerance in `default_weights_sum_to_one`
from 1e-9 to 1e-3 to match Elixir's `assert_in_delta total, 1.0,
0.001` — gradient-descent fits land near 1.0 but not exact.
- Regenerate `tests/scores.bincode` from `mix rust.golden` so the
golden fixture reflects the recalibrated scorer outputs.
`cargo clippy --all-targets -- -D warnings` clean.
139 Rust unit tests + golden fixture pass.
3072 Elixir tests pass.