feat(family-09): add 7 trailing stops (HiLo, Volty, Yo-Yo, Donchian, Pct, Step, Renko) (#46)

* feat(family-09): add 7 trailing stops (HiLo, Volty, Yo-Yo, Donchian, Pct, Step, Renko)

Rounds out the Trailing Stops family from 5 to 12 indicators:

- HiLoActivator (Crabel): SMA-of-high/SMA-of-low trail with a one-bar
  lag; emits the opposite-side SMA as the trailing stop.
- VoltyStop (Cynthia Kase): ATR trail anchored on the extreme close
  since the trade was opened — tighter than AtrTrailingStop on
  pullbacks.
- YoyoExit: long-only ATR trail with an explicit re-entry trigger at
  trail + multiplier*ATR; exposes an in_trade flag.
- DonchianStop (Turtle): lowest low / highest high over the window;
  multi-output {stop_long, stop_short}.
- PercentageTrailingStop: fixed-percent trail that scales across
  instruments without per-asset tuning.
- StepTrailingStop: snaps to a step_size-aligned grid; mirrors
  discretionary stop-by-hand workflow.
- RenkoTrailingStop: block-anchored trail; only moves on full-block
  advances, ignores intra-block noise.

All seven are wired into wickra-core, the Python / Node / WASM
bindings, the indicator_update + indicator_update_candle fuzz targets,
the wickra bench harness, and the Python + Node test suites. README
counter bumps from 71 to 78; CHANGELOG entry under [Unreleased].

* fix(family-09): satisfy pedantic clippy lints

- hilo_activator: rewrite match-Some/None as if-let-else (single_match_else),
  add backticks around the HiLo identifier in module/struct doc (doc_markdown).
- percentage / step / renko trailing stop tests: use f64::from(i32) instead
  of `as f64` (cast_lossless).
- bench `benches()` is now >100 lines after Family 09 was wired in; allow
  too_many_lines (matches the python pymodule fn).

fuzz/fuzz_targets/indicator_update.rs

@@ -18,9 +18,10 @@ use wickra_core::{
     Alma, Apo, BatchExt, BollingerBands, Cfo, Cmo, ConnorsRsi, Coppock, Dema, DoubleBollinger, Dpo,
     ElderImpulse, Ema, Frama, HistoricalVolatility, Hma, Indicator, Jma, Kama, Kst, LaguerreRsi,
     LinRegAngle, LinRegChannel, LinRegSlope, LinearRegression, MaEnvelope, MacdIndicator,
-    McGinleyDynamic, Mom, Pmo, Ppo, Roc, Rsi, RviVolatility, Sma, Smma, StandardErrorBands, Stc,
-    StdDev, StochRsi, T3, Tema, Tii, Trima, Trix, Tsi, UlcerIndex, VerticalHorizontalFilter, Vidya,
-    Wma, ZScore, ZeroLagMacd, Zlema,
+    McGinleyDynamic, Mom, PercentageTrailingStop, Pmo, Ppo, RenkoTrailingStop, Roc, Rsi,
+    RviVolatility, Sma, Smma, StandardErrorBands, Stc, StdDev, StepTrailingStop, StochRsi, T3, Tema,
+    Tii, Trima, Trix, Tsi, UlcerIndex, VerticalHorizontalFilter, Vidya, Wma, ZScore, ZeroLagMacd,
+    Zlema,
 };
 
 /// Drive a single streaming + batch run through one scalar indicator. Marked
@@ -106,6 +107,11 @@ fuzz_target!(|data: Vec<f64>| {
         let _ = ZeroLagMacd::classic().batch(&data);
     }
 
+    // --- Trailing Stops (scalar) ---
+    drive(|| PercentageTrailingStop::new(5.0).unwrap(), &data);
+    drive(|| StepTrailingStop::new(1.0).unwrap(), &data);
+    drive(|| RenkoTrailingStop::new(1.0).unwrap(), &data);
+
     // MACD and Bollinger Bands have non-`f64` outputs, so they cannot use the
     // generic `drive` helper above. Streaming + batch are still both exercised.
     {

fuzz/fuzz_targets/indicator_update_candle.rs

@@ -27,13 +27,13 @@ use wickra_core::{
     AnchoredVwap, Aroon, AroonOscillator, Atr, AtrBands, AtrTrailingStop, AwesomeOscillator,
     AwesomeOscillatorHistogram, BalanceOfPower, BatchExt, Candle, Cci, ChaikinMoneyFlow,
     ChaikinOscillator, ChaikinVolatility, ChandeKrollStop, ChandelierExit, ChoppinessIndex,
-    DemandIndex, Donchian, EaseOfMovement, Evwma, ForceIndex, FractalChaosBands,
-    GarmanKlassVolatility, HurstChannel, Indicator, Inertia, Keltner, Kvo, MarketFacilitationIndex,
-    MassIndex, MedianPrice, Mfi, Natr, Nvi, Obv, ParkinsonVolatility, Pgo, Psar, Pvi,
-    RogersSatchellVolatility, RollingVwap, Rvi, Rwi, Smi, StarcBands, Stochastic, SuperTrend,
-    TrueRange, Tsv, TtmSqueeze, TypicalPrice, UltimateOscillator, VolumeOscillator,
-    VolumePriceTrend, Vortex, Vwap, VwapStdDevBands, Vwma, Vzo, WaveTrend, WeightedClose, WilliamsR,
-    YangZhangVolatility,
+    DemandIndex, Donchian, DonchianStop, EaseOfMovement, Evwma, ForceIndex, FractalChaosBands,
+    GarmanKlassVolatility, HiLoActivator, HurstChannel, Indicator, Inertia, Keltner, Kvo,
+    MarketFacilitationIndex, MassIndex, MedianPrice, Mfi, Natr, Nvi, Obv, ParkinsonVolatility, Pgo,
+    Psar, Pvi, RogersSatchellVolatility, RollingVwap, Rvi, Rwi, Smi, StarcBands, Stochastic,
+    SuperTrend, TrueRange, Tsv, TtmSqueeze, TypicalPrice, UltimateOscillator, VoltyStop,
+    VolumeOscillator, VolumePriceTrend, Vortex, Vwap, VwapStdDevBands, Vwma, Vzo, WaveTrend,
+    WeightedClose, WilliamsR, YangZhangVolatility, YoyoExit,
 };
 
 /// Convert a flat `f64` stream into a `Vec<Candle>` by chunking it into
@@ -93,6 +93,9 @@ fuzz_target!(|data: Vec<f64>| {
     drive(|| ChandelierExit::new(22, 3.0).unwrap(), &candles);
     drive(|| ChandeKrollStop::new(10, 1.0, 9).unwrap(), &candles);
     drive(|| AtrTrailingStop::new(14, 3.0).unwrap(), &candles);
+    drive(|| HiLoActivator::new(3).unwrap(), &candles);
+    drive(|| VoltyStop::new(14, 2.0).unwrap(), &candles);
+    drive(|| YoyoExit::new(14, 2.0).unwrap(), &candles);
 
     // --- Trend & Directional ---
     drive(|| Adx::new(14).unwrap(), &candles);
@@ -160,6 +163,15 @@ fuzz_target!(|data: Vec<f64>| {
         let _ = Stochastic::new(14, 3).unwrap().batch(&candles);
     }
 
+    // --- Donchian Stop (multi-output) ---
+    {
+        let mut s = DonchianStop::new(10).unwrap();
+        for c in &candles {
+            let _ = s.update(*c);
+        }
+        let _ = DonchianStop::new(10).unwrap().batch(&candles);
+    }
+
     // --- Family 05: candle-input band/channel indicators (multi-output) ---
     {
         let mut ab = AccelerationBands::new(20, 0.001).unwrap();