feat(mcginley): add McGinley Dynamic moving average

John McGinley's self-adjusting moving average with the recurrence
MD + (price - MD) / (0.6 * period * (price / MD)^4). Speeds up when
price falls below the indicator and damps when price runs above the
indicator. Seeded with the simple average of the first period inputs.

Reference: McGinley, Technical Analysis of Stocks & Commodities, 1990.

Touchpoints:
- crates/wickra-core: mcginley_dynamic.rs + mod.rs + lib.rs re-export
- bindings/python: PyMcGinleyDynamic + __init__.py + test_new_indicators
  + test_known_values reference
- bindings/node: McGinleyDynamicNode (scalar macro) + index.d.ts/index.js
  + indicators.test.js factory + reference value
- bindings/wasm: wasm_scalar_indicator! macro
- fuzz: indicator_update target covers McGinleyDynamic(10)
- crates/wickra/benches: bench_scalar entry
- README + CHANGELOG: Moving Averages row + Unreleased entry

fuzz/fuzz_targets/indicator_update.rs

@@ -16,8 +16,8 @@
 use libfuzzer_sys::fuzz_target;
 use wickra_core::{
     Alma, BatchExt, BollingerBands, Cmo, Coppock, Dema, Dpo, Ema, HistoricalVolatility, Hma,
-    Indicator, Kama, LinRegAngle, LinRegSlope, LinearRegression, MacdIndicator, Mom, Pmo, Ppo, Roc,
-    Rsi, Sma, Smma, StdDev, StochRsi, T3, Tema, Trima, Trix, Tsi, UlcerIndex,
+    Indicator, Kama, LinRegAngle, LinRegSlope, LinearRegression, MacdIndicator, McGinleyDynamic,
+    Mom, Pmo, Ppo, Roc, Rsi, Sma, Smma, StdDev, StochRsi, T3, Tema, Trima, Trix, Tsi, UlcerIndex,
     VerticalHorizontalFilter, Wma, ZScore, Zlema,
 };
 
@@ -54,6 +54,7 @@ fuzz_target!(|data: Vec<f64>| {
     drive(|| Zlema::new(14).unwrap(), &data);
     drive(|| Kama::new(10, 2, 30).unwrap(), &data);
     drive(|| Alma::new(9, 0.85, 6.0).unwrap(), &data);
+    drive(|| McGinleyDynamic::new(10).unwrap(), &data);
     drive(|| T3::new(14, 0.7).unwrap(), &data);
     drive(|| Mom::new(14).unwrap(), &data);
     drive(|| Cmo::new(14).unwrap(), &data);