fix(rust/scorer): sync recalibrated default weights with Elixir

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.

rust/prop_grid_rs/src/band_config.rs

@@ -55,20 +55,22 @@ impl Weights {
     }
 }
 
-/// Default weight vector fit by gradient descent on 5,000 QSOs
-/// (2026-04-11). Used as fallback for bands that don't carry a `weights`
-/// override.
+/// Default weight vector fit by gradient descent on the current contact
+/// corpus (val loss 0.140 vs 0.146 train, refit 2026-04-28). Mirrors the
+/// `@weights` map in `lib/microwaveprop/propagation/band_config.ex` —
+/// must stay in sync any time `mix recalibrate_scorer` is run on the
+/// Elixir side, otherwise `tests/scorer_golden.rs` will diverge.
 pub const DEFAULT_WEIGHTS: Weights = Weights::new(
-    0.1243, // humidity
-    0.0496, // time_of_day
-    0.0978, // td_depression
-    0.1049, // refractivity
-    0.08,   // sky
-    0.1112, // season
-    0.08,   // wind
-    0.1362, // rain
-    0.1032, // pressure
-    0.1128, // pwat
+    0.1262, // humidity
+    0.0380, // time_of_day
+    0.1010, // td_depression
+    0.0986, // refractivity
+    0.0841, // sky
+    0.1134, // season
+    0.0841, // wind
+    0.1431, // rain
+    0.0967, // pressure
+    0.1147, // pwat
 );
 
 /// Sunrise hour by month (1..=12) in local solar time. Index = month - 1.
@@ -792,8 +794,9 @@ mod tests {
             + w.rain
             + w.pressure
             + w.pwat;
-        // Elixir comment says "all 10 values sum to 1.0" — allow tiny FP slop.
-        assert!((sum - 1.0).abs() < 1e-9, "weights sum = {sum}");
+        // Match the Elixir-side tolerance (`assert_in_delta total, 1.0, 0.001`)
+        // — gradient-descent fits land near 1.0 but not exact.
+        assert!((sum - 1.0).abs() < 1.0e-3, "weights sum = {sum}");
     }
 
     #[test]