F5: add PPO, DPO and Coppock Curve price oscillators

Completes the F5 family (Price oscillators) end to end:

- Rust core: ppo.rs (Percentage Price Oscillator — MACD as a percentage
  of the slow EMA), dpo.rs (Detrended Price Oscillator — shifted price
  minus its SMA), coppock.rs (Coppock Curve — WMA of two summed ROCs).
  Each with a full Indicator impl, runnable doctest and reference /
  constant-series / warmup / reset / batch==streaming / non-finite tests.
- Python: PyPpo / PyDpo / PyCoppock PyO3 classes + module registration
  + .pyi stubs (defaults PPO=(12,26), DPO=20, Coppock=(14,11,10)).
- Node: DpoNode via the scalar macro, explicit PpoNode and CoppockNode;
  index.d.ts and index.js updated.
- WASM: WasmDpo / WasmPpo / WasmCoppock via the scalar macro.
- Wiki: Indicator-Ppo/Dpo/Coppock.md plus rows in Indicators-Overview.md
  and entries in Home.md.

cargo fmt + clippy (core/wickra/data/wasm/node) clean; 300 core tests,
25 data tests and 42 doctests green.

bindings/node/index.js

@@ -310,7 +310,7 @@ if (!nativeBinding) {
   throw new Error(`Failed to load native binding`)
 }
 
-const { version, SMA, EMA, WMA, RSI, DEMA, TEMA, HMA, ROC, TRIX, SMMA, TRIMA, ZLEMA, T3, VWMA, MOM, CMO, TSI, PMO, StochRSI, UltimateOscillator, MACD, BollingerBands, ATR, Stochastic, OBV, ADX, CCI, WilliamsR, MFI, PSAR, Keltner, Donchian, VWAP, AwesomeOscillator, Aroon, KAMA } = nativeBinding
+const { version, SMA, EMA, WMA, RSI, DEMA, TEMA, HMA, ROC, TRIX, SMMA, TRIMA, ZLEMA, T3, VWMA, MOM, CMO, TSI, PMO, StochRSI, UltimateOscillator, PPO, DPO, Coppock, MACD, BollingerBands, ATR, Stochastic, OBV, ADX, CCI, WilliamsR, MFI, PSAR, Keltner, Donchian, VWAP, AwesomeOscillator, Aroon, KAMA } = nativeBinding
 
 module.exports.version = version
 module.exports.SMA = SMA
@@ -333,6 +333,9 @@ module.exports.TSI = TSI
 module.exports.PMO = PMO
 module.exports.StochRSI = StochRSI
 module.exports.UltimateOscillator = UltimateOscillator
+module.exports.PPO = PPO
+module.exports.DPO = DPO
+module.exports.Coppock = Coppock
 module.exports.MACD = MACD
 module.exports.BollingerBands = BollingerBands
 module.exports.ATR = ATR

bindings/node/src/lib.rs

@@ -107,6 +107,7 @@ node_scalar_indicator!(TrimaNode, "TRIMA", wc::Trima);
 node_scalar_indicator!(ZlemaNode, "ZLEMA", wc::Zlema);
 node_scalar_indicator!(MomNode, "MOM", wc::Mom);
 node_scalar_indicator!(CmoNode, "CMO", wc::Cmo);
+node_scalar_indicator!(DpoNode, "DPO", wc::Dpo);
 
 // ============================== MACD ==============================
 
@@ -1238,6 +1239,81 @@ impl UltimateOscillatorNode {
     }
 }
 
+// ============================== PPO ==============================
+
+#[napi(js_name = "PPO")]
+pub struct PpoNode {
+    inner: wc::Ppo,
+}
+
+#[napi]
+impl PpoNode {
+    #[napi(constructor)]
+    pub fn new(fast: u32, slow: u32) -> napi::Result<Self> {
+        Ok(Self {
+            inner: wc::Ppo::new(fast as usize, slow as usize).map_err(map_err)?,
+        })
+    }
+    #[napi]
+    pub fn update(&mut self, value: f64) -> Option<f64> {
+        self.inner.update(value)
+    }
+    #[napi]
+    pub fn batch(&mut self, prices: Vec<f64>) -> Vec<f64> {
+        flatten(self.inner.batch(&prices))
+    }
+    #[napi]
+    pub fn reset(&mut self) {
+        self.inner.reset();
+    }
+    #[napi(js_name = "isReady")]
+    pub fn is_ready(&self) -> bool {
+        self.inner.is_ready()
+    }
+    #[napi(js_name = "warmupPeriod")]
+    pub fn warmup_period(&self) -> u32 {
+        self.inner.warmup_period() as u32
+    }
+}
+
+// ============================== Coppock ==============================
+
+#[napi(js_name = "Coppock")]
+pub struct CoppockNode {
+    inner: wc::Coppock,
+}
+
+#[napi]
+impl CoppockNode {
+    #[napi(constructor)]
+    pub fn new(roc_long: u32, roc_short: u32, wma_period: u32) -> napi::Result<Self> {
+        Ok(Self {
+            inner: wc::Coppock::new(roc_long as usize, roc_short as usize, wma_period as usize)
+                .map_err(map_err)?,
+        })
+    }
+    #[napi]
+    pub fn update(&mut self, value: f64) -> Option<f64> {
+        self.inner.update(value)
+    }
+    #[napi]
+    pub fn batch(&mut self, prices: Vec<f64>) -> Vec<f64> {
+        flatten(self.inner.batch(&prices))
+    }
+    #[napi]
+    pub fn reset(&mut self) {
+        self.inner.reset();
+    }
+    #[napi(js_name = "isReady")]
+    pub fn is_ready(&self) -> bool {
+        self.inner.is_ready()
+    }
+    #[napi(js_name = "warmupPeriod")]
+    pub fn warmup_period(&self) -> u32 {
+        self.inner.warmup_period() as u32
+    }
+}
+
 #[napi(js_name = "VWMA")]
 pub struct VwmaNode {
     inner: wc::Vwma,