F13a: add Accelerator Oscillator, Balance of Power, Choppiness Index and Vertical Horizontal Filter

First half of the eight indicators that fill out the new family taxonomy.

- Rust core: accelerator_oscillator.rs (AcceleratorOscillator — AO minus a
  short SMA of itself), balance_of_power.rs (BalanceOfPower — per-bar
  (close-open)/(high-low)), choppiness_index.rs (ChoppinessIndex — summed
  true range over the high-low span, log-scaled) and
  vertical_horizontal_filter.rs (VerticalHorizontalFilter — net move over
  total move). Each with a full Indicator impl, runnable doctest and
  reference / property / warmup / reset / batch==streaming tests.
- Python / Node / WASM: classes wired through all three bindings
  (BalanceOfPower carries an explicit open column; VHF rides the scalar
  macros) plus .pyi stubs and __init__.py / __all__ entries.
- Wiki: four new Indicator-*.md pages.

The eight-family taxonomy restructure (Overview / Home / README / folder
layout) lands in F13c once F13b's four indicators are in.

cargo fmt + clippy (core/wickra/data/wasm/node) clean; 481 core tests,
25 data tests and 70 doctests green.

crates/wickra-core/src/lib.rs

@@ -44,16 +44,16 @@ pub mod indicators;
 
 pub use error::{Error, Result};
 pub use indicators::{
-    Adl, Adx, AdxOutput, Aroon, AroonOscillator, AroonOutput, Atr, AtrTrailingStop,
-    AwesomeOscillator, BollingerBands, BollingerBandwidth, BollingerOutput, Cci, ChaikinMoneyFlow,
-    ChaikinOscillator, ChandeKrollStop, ChandeKrollStopOutput, ChandelierExit,
-    ChandelierExitOutput, Cmo, Coppock, Dema, Donchian, DonchianOutput, Dpo, EaseOfMovement, Ema,
-    ForceIndex, HistoricalVolatility, Hma, Kama, Keltner, KeltnerOutput, LinRegSlope,
-    LinearRegression, MacdIndicator, MacdOutput, MassIndex, MedianPrice, Mfi, Mom, Natr, Obv,
-    PercentB, Pmo, Ppo, Psar, Roc, RollingVwap, Rsi, Sma, Smma, StdDev, StochRsi, Stochastic,
-    StochasticOutput, SuperTrend, SuperTrendOutput, Tema, Trima, Trix, Tsi, TypicalPrice,
-    UlcerIndex, UltimateOscillator, VolumePriceTrend, Vortex, VortexOutput, Vwap, Vwma,
-    WeightedClose, WilliamsR, Wma, Zlema, T3,
+    AcceleratorOscillator, Adl, Adx, AdxOutput, Aroon, AroonOscillator, AroonOutput, Atr,
+    AtrTrailingStop, AwesomeOscillator, BalanceOfPower, BollingerBands, BollingerBandwidth,
+    BollingerOutput, Cci, ChaikinMoneyFlow, ChaikinOscillator, ChandeKrollStop,
+    ChandeKrollStopOutput, ChandelierExit, ChandelierExitOutput, ChoppinessIndex, Cmo, Coppock,
+    Dema, Donchian, DonchianOutput, Dpo, EaseOfMovement, Ema, ForceIndex, HistoricalVolatility,
+    Hma, Kama, Keltner, KeltnerOutput, LinRegSlope, LinearRegression, MacdIndicator, MacdOutput,
+    MassIndex, MedianPrice, Mfi, Mom, Natr, Obv, PercentB, Pmo, Ppo, Psar, Roc, RollingVwap, Rsi,
+    Sma, Smma, StdDev, StochRsi, Stochastic, StochasticOutput, SuperTrend, SuperTrendOutput, Tema,
+    Trima, Trix, Tsi, TypicalPrice, UlcerIndex, UltimateOscillator, VerticalHorizontalFilter,
+    VolumePriceTrend, Vortex, VortexOutput, Vwap, Vwma, WeightedClose, WilliamsR, Wma, Zlema, T3,
 };
 pub use ohlcv::{Candle, Tick};
 pub use traits::{BatchExt, Chain, Indicator};