* feat(bands-channels): add Family 05 with 11 indicators
Eleven price-envelope overlays organised into a new "Bands & Channels"
family, exposed across all four bindings (Rust core, Python, Node, WASM)
plus fuzz/test/bench/docs coverage:
- MaEnvelope - SMA centerline with fixed-percent envelope (the oldest
band overlay still in regular use).
- AccelerationBands (Price Headley) - momentum-biased bands that widen
with the bar's relative range (H - L) / (H + L).
- StarcBands (Stoller Average Range Channel) - SMA(close) +/- k*ATR;
Keltner's SMA-centerline sibling.
- AtrBands - close-anchored envelope of width k*ATR; the standard
volatility-targeting stop/target band.
- HurstChannel - SMA centerline wrapped by the rolling high-low range
(Brian Millard / Hurst-cycle channel).
- LinRegChannel - rolling OLS endpoint +/- k * population stddev of the
residuals; dispersion about the trend rather than the mean.
- StandardErrorBands - regression line +/- k * OLS standard error
(denominator n - 2) for prediction-interval bands.
- DoubleBollinger (Kathy Lien) - two concentric BB envelopes
(typically +/- 1 sigma and +/- 2 sigma) for the zone-partition setup.
- TtmSqueeze (John Carter) - BB-inside-KC squeeze flag paired with a
detrended-close linear-regression momentum reading.
- FractalChaosBands - Bill Williams 5-bar fractal high/low envelope.
- VwapStdDevBands - cumulative VWAP with volume-weighted population
standard deviation bands.
Each indicator ships:
- Core impl with the full Indicator trait, classic() where applicable,
and unit tests (rejects_zero_period / multiplier, accessors, flat
market, monotonic ordering, batch == streaming, reset, plus
algebraically verifiable reference values).
- Python PyO3 binding with multi-column NumPy batch (PyArray2).
- Node napi binding with #[napi(object)] struct + interleaved flat
batch.
- WASM wasm-bindgen binding via Object/Reflect for update +
Float64Array for batch.
- Fuzz coverage in fuzz_targets/indicator_update{,_candle}.rs.
- Python streaming-vs-batch parametric test + reference test.
- Node streaming-vs-interleaved-batch test + reference test.
- Criterion microbench under crates/wickra/benches/indicators.rs.
README family table, README indicator-count line, and CHANGELOG
Unreleased entry updated: indicator total rises from 71 to 82 across
nine families. Wiki pages are updated in a separate commit in the
wickra.wiki repo.
* test(acceleration-bands): cover sum_hl==0 zero-price guard
Exercises line 104 (`0.0` branch of the `sum_hl == 0.0` guard) which
was the last patch-coverage miss on the family-05 PR. `Candle::new`
accepts a fully-zero bar so the branch is reachable in principle —
add a degenerate-candle unit test to hit it.
kingchenc
54194a4ff8