Add B7 Trailing Stops family (6 indicators) (#193)

Adds the **Trailing Stops** family deepening (B7), six new indicators (434 -> 440):

- **KaseDevStop** — Cynthia Kase's volatility stop on the standard deviation of the two-bar true range.
- **ElderSafeZone** — Alexander Elder's stop offset by a multiple of average market noise.
- **AtrRatchet** — Kaufman ATR ratchet that tightens its multiple by a per-bar increment.
- **Nrtr** — Nick Rypock Trailing Reverse (percentage band).
- **TimeBasedStop** — exits after a fixed number of bars (scalar fraction of elapsed life).
- **ModifiedMaStop** — moving-average based trailing stop.

("Wilder Volatility System" is intentionally skipped — it overlaps the existing VoltyStop/Psar/SarExt.)

Each takes Candle input; the five band/structure stops emit a {value, direction} struct, TimeBasedStop a scalar. Wired across core, Python/Node/WASM bindings, fuzz target and tests. Verified locally: 3560 core lib + 398 doc tests, clippy clean, 515 node tests, 852 pytest, counter 440.

bindings/wasm/src/lib.rs

@@ -2552,6 +2552,44 @@ impl WasmProjectionOscillator {
     }
 }
 
+#[wasm_bindgen(js_name = TimeBasedStop)]
+pub struct WasmTimeBasedStop {
+    inner: wc::TimeBasedStop,
+}
+
+#[wasm_bindgen(js_class = TimeBasedStop)]
+impl WasmTimeBasedStop {
+    #[wasm_bindgen(constructor)]
+    pub fn new(max_bars: usize) -> Result<WasmTimeBasedStop, JsError> {
+        Ok(Self {
+            inner: wc::TimeBasedStop::new(max_bars).map_err(map_err)?,
+        })
+    }
+    pub fn update(&mut self, high: f64, low: f64, close: f64) -> Result<Option<f64>, JsError> {
+        let c = make_candle(high, low, close, 0.0)?;
+        Ok(self.inner.update(c))
+    }
+    pub fn batch(
+        &mut self,
+        high: &[f64],
+        low: &[f64],
+        close: &[f64],
+    ) -> Result<Float64Array, JsError> {
+        if high.len() != low.len() || low.len() != close.len() {
+            return Err(JsError::new("high, low, close must be equal length"));
+        }
+        let mut out = Vec::with_capacity(high.len());
+        for i in 0..high.len() {
+            let c = make_candle(high[i], low[i], close[i], 0.0)?;
+            out.push(self.inner.update(c).unwrap_or(f64::NAN));
+        }
+        Ok(Float64Array::from(out.as_slice()))
+    }
+    pub fn reset(&mut self) {
+        self.inner.reset();
+    }
+}
+
 #[wasm_bindgen(js_name = Stochastic)]
 pub struct WasmStoch {
     inner: wc::Stochastic,
@@ -3833,6 +3871,275 @@ impl WasmRenkoTrailingStop {
     }
 }
 
+#[wasm_bindgen(js_name = KaseDevStop)]
+pub struct WasmKaseDevStop {
+    inner: wc::KaseDevStop,
+}
+
+#[wasm_bindgen(js_class = KaseDevStop)]
+impl WasmKaseDevStop {
+    #[wasm_bindgen(constructor)]
+    pub fn new(period: usize, dev: f64) -> Result<WasmKaseDevStop, JsError> {
+        Ok(Self {
+            inner: wc::KaseDevStop::new(period, dev).map_err(map_err)?,
+        })
+    }
+    /// Returns `{ value, direction }` once warm, else `null`.
+    pub fn update(&mut self, high: f64, low: f64, close: f64) -> Result<JsValue, JsError> {
+        let c = make_candle(high, low, close, 0.0)?;
+        Ok(match self.inner.update(c) {
+            Some(o) => {
+                let obj = Object::new();
+                Reflect::set(&obj, &"value".into(), &o.value.into()).ok();
+                Reflect::set(&obj, &"direction".into(), &o.direction.into()).ok();
+                obj.into()
+            }
+            None => JsValue::NULL,
+        })
+    }
+    /// Returns `[value0, direction0, value1, direction1, ...]`, length `2 * n`.
+    /// Warmup is NaN.
+    pub fn batch(
+        &mut self,
+        high: &[f64],
+        low: &[f64],
+        close: &[f64],
+    ) -> Result<Float64Array, JsError> {
+        let n = high.len();
+        if low.len() != n || close.len() != n {
+            return Err(JsError::new("high, low, close must be equal length"));
+        }
+        let mut out = vec![f64::NAN; n * 2];
+        for i in 0..n {
+            let c = make_candle(high[i], low[i], close[i], 0.0)?;
+            if let Some(o) = self.inner.update(c) {
+                out[i * 2] = o.value;
+                out[i * 2 + 1] = o.direction;
+            }
+        }
+        Ok(Float64Array::from(out.as_slice()))
+    }
+    pub fn reset(&mut self) {
+        self.inner.reset();
+    }
+}
+
+#[wasm_bindgen(js_name = ElderSafeZone)]
+pub struct WasmElderSafeZone {
+    inner: wc::ElderSafeZone,
+}
+
+#[wasm_bindgen(js_class = ElderSafeZone)]
+impl WasmElderSafeZone {
+    #[wasm_bindgen(constructor)]
+    pub fn new(period: usize, coeff: f64) -> Result<WasmElderSafeZone, JsError> {
+        Ok(Self {
+            inner: wc::ElderSafeZone::new(period, coeff).map_err(map_err)?,
+        })
+    }
+    /// Returns `{ value, direction }` once warm, else `null`.
+    pub fn update(&mut self, high: f64, low: f64, close: f64) -> Result<JsValue, JsError> {
+        let c = make_candle(high, low, close, 0.0)?;
+        Ok(match self.inner.update(c) {
+            Some(o) => {
+                let obj = Object::new();
+                Reflect::set(&obj, &"value".into(), &o.value.into()).ok();
+                Reflect::set(&obj, &"direction".into(), &o.direction.into()).ok();
+                obj.into()
+            }
+            None => JsValue::NULL,
+        })
+    }
+    /// Returns `[value0, direction0, value1, direction1, ...]`, length `2 * n`.
+    /// Warmup is NaN.
+    pub fn batch(
+        &mut self,
+        high: &[f64],
+        low: &[f64],
+        close: &[f64],
+    ) -> Result<Float64Array, JsError> {
+        let n = high.len();
+        if low.len() != n || close.len() != n {
+            return Err(JsError::new("high, low, close must be equal length"));
+        }
+        let mut out = vec![f64::NAN; n * 2];
+        for i in 0..n {
+            let c = make_candle(high[i], low[i], close[i], 0.0)?;
+            if let Some(o) = self.inner.update(c) {
+                out[i * 2] = o.value;
+                out[i * 2 + 1] = o.direction;
+            }
+        }
+        Ok(Float64Array::from(out.as_slice()))
+    }
+    pub fn reset(&mut self) {
+        self.inner.reset();
+    }
+}
+
+#[wasm_bindgen(js_name = AtrRatchet)]
+pub struct WasmAtrRatchet {
+    inner: wc::AtrRatchet,
+}
+
+#[wasm_bindgen(js_class = AtrRatchet)]
+impl WasmAtrRatchet {
+    #[wasm_bindgen(constructor)]
+    pub fn new(
+        atr_period: usize,
+        start_mult: f64,
+        increment: f64,
+    ) -> Result<WasmAtrRatchet, JsError> {
+        Ok(Self {
+            inner: wc::AtrRatchet::new(atr_period, start_mult, increment).map_err(map_err)?,
+        })
+    }
+    /// Returns `{ value, direction }` once warm, else `null`.
+    pub fn update(&mut self, high: f64, low: f64, close: f64) -> Result<JsValue, JsError> {
+        let c = make_candle(high, low, close, 0.0)?;
+        Ok(match self.inner.update(c) {
+            Some(o) => {
+                let obj = Object::new();
+                Reflect::set(&obj, &"value".into(), &o.value.into()).ok();
+                Reflect::set(&obj, &"direction".into(), &o.direction.into()).ok();
+                obj.into()
+            }
+            None => JsValue::NULL,
+        })
+    }
+    /// Returns `[value0, direction0, value1, direction1, ...]`, length `2 * n`.
+    /// Warmup is NaN.
+    pub fn batch(
+        &mut self,
+        high: &[f64],
+        low: &[f64],
+        close: &[f64],
+    ) -> Result<Float64Array, JsError> {
+        let n = high.len();
+        if low.len() != n || close.len() != n {
+            return Err(JsError::new("high, low, close must be equal length"));
+        }
+        let mut out = vec![f64::NAN; n * 2];
+        for i in 0..n {
+            let c = make_candle(high[i], low[i], close[i], 0.0)?;
+            if let Some(o) = self.inner.update(c) {
+                out[i * 2] = o.value;
+                out[i * 2 + 1] = o.direction;
+            }
+        }
+        Ok(Float64Array::from(out.as_slice()))
+    }
+    pub fn reset(&mut self) {
+        self.inner.reset();
+    }
+}
+
+#[wasm_bindgen(js_name = Nrtr)]
+pub struct WasmNrtr {
+    inner: wc::Nrtr,
+}
+
+#[wasm_bindgen(js_class = Nrtr)]
+impl WasmNrtr {
+    #[wasm_bindgen(constructor)]
+    pub fn new(pct: f64) -> Result<WasmNrtr, JsError> {
+        Ok(Self {
+            inner: wc::Nrtr::new(pct).map_err(map_err)?,
+        })
+    }
+    /// Returns `{ value, direction }` once warm, else `null`.
+    pub fn update(&mut self, high: f64, low: f64, close: f64) -> Result<JsValue, JsError> {
+        let c = make_candle(high, low, close, 0.0)?;
+        Ok(match self.inner.update(c) {
+            Some(o) => {
+                let obj = Object::new();
+                Reflect::set(&obj, &"value".into(), &o.value.into()).ok();
+                Reflect::set(&obj, &"direction".into(), &o.direction.into()).ok();
+                obj.into()
+            }
+            None => JsValue::NULL,
+        })
+    }
+    /// Returns `[value0, direction0, value1, direction1, ...]`, length `2 * n`.
+    /// Warmup is NaN.
+    pub fn batch(
+        &mut self,
+        high: &[f64],
+        low: &[f64],
+        close: &[f64],
+    ) -> Result<Float64Array, JsError> {
+        let n = high.len();
+        if low.len() != n || close.len() != n {
+            return Err(JsError::new("high, low, close must be equal length"));
+        }
+        let mut out = vec![f64::NAN; n * 2];
+        for i in 0..n {
+            let c = make_candle(high[i], low[i], close[i], 0.0)?;
+            if let Some(o) = self.inner.update(c) {
+                out[i * 2] = o.value;
+                out[i * 2 + 1] = o.direction;
+            }
+        }
+        Ok(Float64Array::from(out.as_slice()))
+    }
+    pub fn reset(&mut self) {
+        self.inner.reset();
+    }
+}
+
+#[wasm_bindgen(js_name = ModifiedMaStop)]
+pub struct WasmModifiedMaStop {
+    inner: wc::ModifiedMaStop,
+}
+
+#[wasm_bindgen(js_class = ModifiedMaStop)]
+impl WasmModifiedMaStop {
+    #[wasm_bindgen(constructor)]
+    pub fn new(period: usize) -> Result<WasmModifiedMaStop, JsError> {
+        Ok(Self {
+            inner: wc::ModifiedMaStop::new(period).map_err(map_err)?,
+        })
+    }
+    /// Returns `{ value, direction }` once warm, else `null`.
+    pub fn update(&mut self, high: f64, low: f64, close: f64) -> Result<JsValue, JsError> {
+        let c = make_candle(high, low, close, 0.0)?;
+        Ok(match self.inner.update(c) {
+            Some(o) => {
+                let obj = Object::new();
+                Reflect::set(&obj, &"value".into(), &o.value.into()).ok();
+                Reflect::set(&obj, &"direction".into(), &o.direction.into()).ok();
+                obj.into()
+            }
+            None => JsValue::NULL,
+        })
+    }
+    /// Returns `[value0, direction0, value1, direction1, ...]`, length `2 * n`.
+    /// Warmup is NaN.
+    pub fn batch(
+        &mut self,
+        high: &[f64],
+        low: &[f64],
+        close: &[f64],
+    ) -> Result<Float64Array, JsError> {
+        let n = high.len();
+        if low.len() != n || close.len() != n {
+            return Err(JsError::new("high, low, close must be equal length"));
+        }
+        let mut out = vec![f64::NAN; n * 2];
+        for i in 0..n {
+            let c = make_candle(high[i], low[i], close[i], 0.0)?;
+            if let Some(o) = self.inner.update(c) {
+                out[i * 2] = o.value;
+                out[i * 2 + 1] = o.direction;
+            }
+        }
+        Ok(Float64Array::from(out.as_slice()))
+    }
+    pub fn reset(&mut self) {
+        self.inner.reset();
+    }
+}
+
 #[wasm_bindgen(js_name = TypicalPrice)]
 pub struct WasmTypicalPrice {
     inner: wc::TypicalPrice,