Adds a Go binding (`bindings/go`) over the C ABI hub — the second language stecker after C#.
## What's here
- **`bindings/go`** — a cgo binding exposing all 514 indicators as idiomatic Go types with `New<Indicator>` constructors and `Update`/`Batch`/`Reset`/`Close` methods. The wrappers in `indicators_gen.go` are generated from `bindings/c/include/wickra.h` (same archetype taxonomy as the C# generator: scalar/batch, multi-output, bars, profile, profile-values, array-input). Opaque handles are freed by `Close()` with a `runtime.SetFinalizer` backstop; pointer arguments are caller-owned, panics never cross the boundary.
- **`examples/go`** — the full example suite mirroring C/C#: streaming, backtest, multi_timeframe, parallel_assets (goroutine fan-out), three strategies, and `fetch_btcusdt`/`live_binance`.
- **CI** — a `go` job builds the C ABI library, stages it, and runs `gofmt`/`go vet`/`go test` plus the offline examples on Linux, macOS and Windows.
- **Docs** — Go added to the README languages table, project layout, building/testing, CONTRIBUTING binding table + regenerate note, ARCHITECTURE, examples index, issue/PR templates, the About-description template, and the other binding READMEs.
## Linking / distribution
The binding links the prebuilt C ABI library via cgo (`libwickra.so`/`.dylib`/`wickra.dll` staged under `bindings/go/lib`, gitignored). The native libraries are already shipped per target triple by the existing `c-abi-build` release job; distribution is via the subdirectory module tag `bindings/go/vX.Y.Z` (gated), so `release.yml` needs no new publish job.
No Rust crate or `Cargo.toml` change — the Go module is standalone and additive.
Not for merge yet (gated, per request).
The first language stecker on the C ABI hub: a .NET binding exposing all 514
indicators as idiomatic `IDisposable` classes, generated from `wickra.h`.
## What's here
- **`bindings/csharp/`** — the `Wickra` .NET 8 package. `[LibraryImport]`
source-generated P/Invoke (`NativeMethods.g.cs`) plus idiomatic wrappers
(`Indicators.g.cs`), both generated from the committed `bindings/c/include/wickra.h`.
The binding owns no indicator maths — it only marshals types across the C ABI.
- **Marshalling, verified end-to-end against the native library.** Opaque handles
cross as `nint` kept alive per call via a `SafeHandle`; `bool` as
`[MarshalAs(U1)]` (Rust `bool` is one byte); a self-correcting
`DllImportResolver` validates the loaded library actually exports the Wickra
ABI. Tests cover one representative per FFI archetype (scalar, candle, pairwise,
multi-output, bars, profile, values-profile, order-book / array-input) plus
exact Sma reference values.
- **NuGet packaging** — `dotnet pack` produces `Wickra.<version>.nupkg`; the
release pipeline stages prebuilt native libraries under `runtimes/<rid>/native/`
for six target triples (win/linux/osx × x64/arm64).
- **`examples/csharp/`** — nine examples mirroring `examples/c/`: streaming,
backtest, multi_timeframe, parallel_assets, three strategies, and
fetch_btcusdt + live_binance.
- **CI** — a `csharp` job on the three OSes builds the C ABI, tests the binding,
and runs the offline examples. **Release** — a gated `csharp-publish` job packs
and pushes to NuGet (gated on `NUGET_API_KEY`, independent of the GitHub-release
job so a C# hiccup never blocks the C/C++ asset release).
- **Docs consistency wave** — README, CONTRIBUTING, CHANGELOG, examples/README,
the issue / PR templates, `sync-about.yml`, and `.gitattributes`.
The native Python / Node / WASM bindings and the C ABI are untouched; this is
additive. Publishing to NuGet stays gated behind the release tag and the secret.
Stacked on #222 (base `feat/c-abi-hub`), so the diff is just the additions on top of the hub foundation — no merge of #222 required.
## What this adds
**Examples — full parity with rust/python/node (`examples/c/`)**
- `streaming.c` upgraded to the multi-indicator (SMA/EMA/RSI/MACD + signals) demo
- `backtest.c`, `multi_timeframe.c` (manual time-bucket resampling), `parallel_assets.c` (serial vs OpenMP fan-out, one handle per asset)
- three educational strategies: `strategy_rsi_mean_reversion.c`, `strategy_macd_adx.c`, `strategy_bollinger_squeeze.c`
- two network examples shelling out to `curl`: `fetch_btcusdt.c`, `live_binance.c` (REST poll)
- two header-only helpers (`wickra_csv.h`, `wickra_strategy.h`) since the C ABI ships no IO layer
- CMake builds all 11; the 9 offline ones run under `ctest` on 3 OS; the network two are built-only
**Docs & metadata — surface the C ABI everywhere it was missing**
- ARCHITECTURE diagram + crate table, SECURITY + THREAT_MODEL (the C ABI as the sole `unsafe` FFI surface), the three binding package READMEs, issue/PR templates, CHANGELOG, and the GitHub About template (live About + org description updated too)
**Cleanup**
- removed all references to the private generator tooling from public files (`bindings/c/src/lib.rs` header, `CONTRIBUTING.md`, `sync-about.yml`)
Verified locally: `cargo build -p wickra-c --release`, `cmake + ctest` (9/9 pass), and `-Wall -Wextra -Wpedantic` clean on gcc 13.
Version bump **0.7.3 → 0.7.4** for the B19 Alt-Chart Bars batch (7 new bar builders, 507 → 514).
Bumps `Cargo.toml` (+ `wickra-core` dep), `Cargo.lock`, `pyproject.toml`, the Node `package.json` and its six platform packages, both `package-lock.json` files, and the CHANGELOG (`[Unreleased]` → `[0.7.4]` with compare URLs).
Version bump **0.7.2 → 0.7.3** for the B18 Risk / Performance batch (9 new indicators, 498 → 507).
Bumps `Cargo.toml` (+ `wickra-core` dep), `Cargo.lock`, `pyproject.toml`, the Node `package.json` and its six platform packages, both `package-lock.json` files, and the CHANGELOG (`[Unreleased]` → `[0.7.3]` with compare URLs).
B13 of the family-deepening roadmap — five alternative-chart indicators (474 -> 479), all in the **Ichimoku & Charts** family.
- **Smoothed Heikin-Ashi** (`candle -> struct {open, high, low, close}`) — a Heikin-Ashi candle computed from EMA-smoothed OHLC.
- **Heikin-Ashi Oscillator** (`candle -> f64`) — the HA body (`ha_close - ha_open`), optionally EMA-smoothed, as a zero-line oscillator.
- **Three Line Break** (`candle -> f64`) — line-break ("kakushi") chart trend direction; reverses only when the close breaks the extreme of the last N lines. Distinct from the candlestick `ThreeLineStrike`.
- **Equivolume** (`candle -> struct {height, width}`) — a box whose height is the bar range and width is volume-relative.
- **CandleVolume** (`candle -> struct {body, width}`) — a candle whose body is close-minus-open and width is volume-relative.
All bindings hand-written (3 struct-output + 2 candle-input-with-open / non-period-ctor). Wiring complete across core, Python, Node, WASM, fuzz, tests, README + docs counter (479) and CHANGELOG. Verified: core 3915 + doc 432, clippy clean, node 554, python 913.
## Summary
- Dedicated batch fast paths for **EMA, RSI, Bollinger, MACD and ATR** (used by the Python bindings): one allocation filled in a single pass, warmup encoded as `NaN`, no per-element `Option` or input re-validation. Each is **bit-for-bit equal** to replaying `update` — SMA/Bollinger keep the drift-reseed cadence, the EMA-family keep the seed division and `mul_add` recurrences. Adds the `BatchNanExt` extension trait.
- **Cross-library benchmark refresh**: `compare_libraries.py` reports the median across timing rounds (`--rounds` / `--streaming-rounds`), gains `--skip-batch` / `--skip-streaming`, and runs every peer through the streaming arena (recompute for batch-only libraries). `wickra-bench` drives the batch fast paths against `kand`.
- **README** benchmark section reordered streaming-first (the order-of-magnitude result), with measured TA-Lib/tulipy/pandas-ta numbers in place of the CI-only placeholders.
## Impact
- Python batch ~2× faster on EMA/RSI/MACD/ATR; streaming path unchanged.
- The `batch == streaming` equivalence stays bit-exact.
## Verification
- `cargo fmt` · `cargo clippy --workspace --all-targets --all-features -- -D warnings` (clean)
- `cargo test --workspace --all-features` — 3782 unit + 420 doc tests pass
- Python `pytest` — streaming-vs-batch, known-values, input-validation, smoke pass
## Notes
- Node/WASM bindings keep their existing batch; the fast paths are Python-only for now.
Adds five support/resistance and pivot indicators, growing the catalog 462 -> 467.
## Indicators
- **CentralPivotRange** (Candle -> struct) — the classic pivot `(H+L+C)/3` flanked by two central levels (TC/BC); range width gauges trending vs balanced days.
- **MurreyMathLines** (Candle -> struct) — T. H. Murrey's eighths grid over a rolling high-low frame; nine levels (0/8 .. 8/8) acting as support/resistance.
- **AndrewsPitchfork** (Candle -> struct) — median line and two parallels projected forward from the last three auto-detected swing pivots (symmetric fractal of half-width `strength`).
- **VolumeWeightedSr** (Candle -> struct) — a band whose edges are the volume-weighted average of recent highs (resistance) and lows (support); falls back to equal weighting when window volume is zero.
- **PivotReversal** (Candle -> f64) — a `+1`/`-1` breakout signal fired on the bar where price closes through the most recently confirmed swing pivot.
## Wiring
Core structs with branch-complete unit tests, Python/Node/WASM bindings, fuzz drives, reference + streaming-vs-batch tests, README + docs counter sync (FAMILIES "Pivots & S/R"), and CHANGELOG entries.
Verified locally: `cargo fmt`, `cargo test -p wickra-core` (3798 lib + 425 doc), `cargo clippy --workspace --all-targets --all-features -D warnings`, `npm run build && npm test` (542), `maturin develop` + `pytest` (891).
Version bump for the **v0.6.5** release shipping the **B10 Ehlers / Cycle** family (#199): 452 -> 462 indicators. Bumps workspace + Python/Node/WASM package versions, lockfiles and CHANGELOG. No code changes.
Version bump for the **v0.6.4** release shipping the **B9 Price Statistics** family (#197): 447 -> 452 indicators. Bumps workspace + Python/Node/WASM package versions, lockfiles and CHANGELOG. No code changes.
Deepens the **Price Statistics** family (B9) with five rolling-statistics indicators (447 -> 452):
- **ShannonEntropy** — Shannon entropy of a binned rolling value distribution.
- **SampleEntropy** — Richman-Moorman sample entropy (regularity/complexity of a window).
- **KendallTau** — Kendall rank correlation (tau-b) over paired observations (pairwise; distinct from Pearson/Spearman).
- **JarqueBera** — Jarque-Bera normality test statistic over a rolling window.
- **RollingMinMaxScaler** — maps the latest value to 0..1 over a rolling window.
All scalar f64 input except KendallTau (pairwise). Multi-arg scalars (Shannon/Sample entropy) use hand-written Python/Node bindings + the variadic wasm macro; KendallTau uses the pair macros. Verified locally: 3668 core lib + 410 doc tests, clippy clean, 527 node tests, 871 pytest, counter 452.
Version bump for the **v0.6.3** release shipping the **B8 Volume** family (#195): 440 -> 447 indicators. Bumps workspace + Python/Node/WASM package versions, lockfiles and CHANGELOG. No code changes.
Deepens the **Volume** family (B8) with seven indicators (440 -> 447):
- **VolumeRsi** — Wilder RSI computed on signed volume flow.
- **WilliamsAd** — Williams Accumulation/Distribution cumulative line (distinct from Chaikin A/D).
- **TwiggsMoneyFlow** — true-range volume accumulation with Wilder smoothing (distinct from CMF).
- **TradeVolumeIndex** — tick-direction volume accumulation past a min-tick threshold (distinct from TSV).
- **IntradayIntensity** — volume weighted by close position within the bar range.
- **BetterVolume** — VSA volume-vs-spread effort/result classifier.
- **VolumeWeightedMacd** — MACD computed on VWMA with signal line and histogram (struct output).
("Up/Down Volume Ratio" already ships from A2.) All Candle input; the six scalar stops emit f64, VolumeWeightedMacd a {macd, signal, histogram} struct. Hand-written Python/Node/WASM bindings for the volume signature. Verified locally: 3620 core lib + 405 doc tests, clippy clean, 522 node tests, 865 pytest, counter 447.
Version bump for the **v0.6.2** release shipping the **B7 Trailing Stops** family (#193): 434 -> 440 indicators.
Bumps workspace + Python/Node/WASM package versions, lockfiles and CHANGELOG (cuts the `[0.6.2]` section). No code changes.
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.
Version bump for the **v0.6.0** release (ships the B5 Volatility & Bands batch, #189 — 423 -> 429 indicators).
Bumps version strings across Cargo workspace, pyproject, node package.json + 6 platform packages, both package-lock.json files, and Cargo.lock; CHANGELOG `[Unreleased]` -> `[0.6.0]`. No code changes.
Versioning note: patch never reaches two digits — `0.5.9` rolls to the next minor `0.6.0` (not 0.5.10).
Adds six **Volatility & Bands** indicators (Part B5 of the expansion roadmap), 423 → 429.
| Indicator | Input → Output | Summary |
|-----------|----------------|---------|
| `EwmaVolatility` | `f64` → `f64` | RiskMetrics exponentially-weighted volatility (λ decay) |
| `Garch11` | `f64` → `f64` | GARCH(1,1) conditional volatility with a long-run-variance anchor |
| `BipowerVariation` | `f64` → `f64` | jump-robust realized bipower variation (π/2 · Σ\|rₜ\|\|rₜ₋₁\|) |
| `VolatilityRatio` | `Candle` → `f64` | Schwager's true range over the EMA of prior true ranges (>2 = wide-ranging day) |
| `VolatilityCone` | `Candle` → `VolatilityConeOutput` | current realized volatility within its min/median/max envelope + percentile |
| `VolatilityOfVolatility` | `f64` → `f64` | sample stddev of a rolling realized-volatility series |
### Notes
- Two B5 roadmap items were dropped as duplicates/by-construction: `RealizedVolatility` already ships (v0.5.4); `Downside Semi-Deviation` is internal to Sortino. `Bipower Variation` confirmed distinct from `JumpIndicator` (a ±1 flag, not a variance measure).
- `VolatilityRatio` implements the widely-charted EMA-of-true-range convention (denominator excludes the current bar so the 2.0 threshold means "twice typical"), distinct from the existing pairwise `variance_ratio`.
- `Garch11` mean-reverts to `ω/(1−β)` on a flat series (does not decay to 0 like EWMA) — pinned by a dedicated test.
### Coverage / verification
- Full core + Python/Node/WASM bindings, fuzz drivers (scalar + candle), registries, CHANGELOG, README + docs counter sync.
- 100% unit-test coverage per indicator (every branch).
- Green locally: `cargo clippy --workspace --all-targets --all-features -D warnings`, core lib (3479) + doc (387), node (504), python (830).
Deep-dive docs for all six are staged for `wickra-docs` and pushed after release (gated).
Patch release: streaming/batch perf (SMA, Bollinger, RSI, EMA, ATR; outputs unchanged), cross-library benchmark harness, honest tiered README. No new indicators, no API changes.
## Summary
An honest, tiered cross-library benchmark — and the optimization pass it triggered.
### Performance (wickra-core, outputs unchanged)
Profiling against the other Rust TA crates exposed real inefficiencies. Each
benchmarked indicator is now **5–79% faster** in both streaming and batch:
- **SMA, Bollinger**: flat `Box<[f64]>` ring buffers replace `VecDeque` (−69…79%).
- **RSI**: `100·ag/(ag+al)` collapses three divisions into one; Wilder smoothing
hoists `1/period` out of the hot path (−46%).
- **ATR**: reciprocal hoisted (−42%).
- **EMA/RSI/ATR**: per-tick `Option<f64>` hot state → bare `f64` + ready flag.
Net result vs `kand`: Wickra now wins **RSI, Bollinger and ATR** (streaming), and
ties `ta-rs` on SMA — up from losing every indicator 1.5–6× before.
### Benchmark harness
New `crates/wickra-bench` (publish=false): a Criterion benchmark comparing Wickra
against `kand`, `ta-rs` and `yata` on an identical BTCUSDT candle series, in
streaming and batch modes. Peer APIs were verified against their source, not
guessed. Wired into the nightly `cross-library-bench` workflow as a separate job.
### Honest README
The benchmark section is rewritten into three layered tables (Rust core vs Rust
crates; Python vs the Python ecosystem) that **show the losses as well as the
wins**. The "only library that combines…" claim is gone; the new framing is
breadth + multi-language reach + the deliberate safety trade-off that costs raw
speed. Added an origin/why-slower rationale and a star CTA.
### Python benchmark
Added `tulipy` runners and expanded per-tick streaming coverage to SMA/EMA/RSI/
MACD/Bollinger. `bench.in`/`bench.txt` now lock `TA-Lib` + `tulipy` (hash-pinned);
`pandas-ta` stays out (it requires Python ≥ 3.12, the bench runs on 3.11).
### Notes
- TA-Lib/tulipy numbers in the README Python table are marked ⧗ — they are
produced by the CI Linux job (C extensions don't build cleanly on every
desktop), not measured locally.
- The matching `wickra-docs` prose update is committed separately and will be
pushed with the release, per the docs-don't-lead-the-registries rule.
Verified locally: `cargo fmt`, `cargo test --workspace --all-features` (3413 core
+ bindings), `cargo clippy --workspace --all-targets --all-features -D warnings`,
Node build + 498 tests, and pytest all green.
Adds three **Price Oscillators** family indicators (420 → 423).
## Indicators
- **TsfOscillator** — `100·(close − TSF)/close`, the percentage gap of the close to the **one-bar-ahead** time-series forecast. Close-relative companion to `Cfo`, which measures the same gap against the regression value at the *current* bar; the two differ by exactly the slope term `100·b/close`.
- **MacdHistogram** — the standalone `macd − signal` bar of MACD exposed as a plain `f64` series.
- **PpoHistogram** — the Percentage Price Oscillator with its 9-period signal EMA and the resulting scale-free, zero-centered histogram (PPO itself only emits the line).
All three are scalar `f64` indicators wrapping existing, already-tested building blocks (`MacdIndicator`, `Ppo` + `Ema`, `Tsf`).
## Scope notes (VORAB-CHECK)
The B4 roadmap listed six items; three were dropped to avoid duplicates:
- *Forecast Oscillator* already ships as `Cfo`.
- *Derivative Oscillator* already ships (`DerivativeOscillator`, B2).
- *Detrended Synthetic Price* deferred — no citable formula distinct from the existing `Apo`/`Dpo`.
## Touchpoints
Core (`tsf_oscillator.rs`, `macd_histogram.rs`, `ppo_histogram.rs`) with full per-branch unit tests, `mod.rs`/`lib.rs`, python/node/wasm bindings (wasm via typed-arg macro, python/node hand-written for the multi-arg histograms), fuzz drivers, python reference + streaming-vs-batch tests, node factories, README family row + counter, CHANGELOG.
Local verify: `cargo test --workspace` green, `clippy -D warnings` clean, node 498 tests, full python suite green.
Version bump 0.5.6 → 0.5.7 for the **B3 — Trend & Directional** batch (#181):
seven new indicators (`Qstick`, `TtmTrend`, `TrendStrengthIndex`,
`PolarizedFractalEfficiency`, `WavePm`, `GatorOscillator`,
`KasePermissionStochastic`), catalog 413 → 420.
Bumps: workspace `Cargo.toml` + `Cargo.lock`, `bindings/python/pyproject.toml`,
`bindings/node/package.json` + the six `npm/*/package.json` platform manifests,
both `package-lock.json` files, and the `CHANGELOG.md` `[Unreleased]` → `[0.5.7]`
roll with compare URLs.
Release bump `0.5.5 → 0.5.6` for the Momentum Oscillators family deepening
(#179): ten new indicators (DisparityIndex, FisherRsi, Rmi, DerivativeOscillator,
Rsx, DynamicMomentumIndex, IntradayMomentumIndex, StochasticCci, ElderRay, Qqe),
counter now 413.
Version strings only across all manifests + lockfiles; CHANGELOG `[Unreleased]`
rolled to `[0.5.6] - 2026-06-04` with the new compare links.
Release bump `0.5.4 → 0.5.5` for the Moving Averages family deepening
(#177): seven new indicators (`SineWeightedMa`, `GeometricMa`, `Ehma`,
`MedianMa`, `AdaptiveLaguerreFilter`, `GeneralizedDema`, `HoltWinters`),
counter now 403.
Version strings only across all manifests + lockfiles; CHANGELOG `[Unreleased]`
rolled to `[0.5.5] - 2026-06-04` with the new compare links.
Deepens the **Moving Averages** family with seven widely-used variants
(396 → 403 indicators), the first batch of Part B (family deepening).
All are scalar `f64 → f64`:
| Indicator | Binding | Notes |
|-----------|---------|-------|
| `SineWeightedMa` | `SWMA` | symmetric half-cycle sine-weighted window |
| `GeometricMa` | `GMA` | rolling geometric mean (log-space average) |
| `Ehma` | `EHMA` | exponential Hull MA (Hull construction over EMAs) |
| `MedianMa` | `MedianMA` | rolling median, robust to single outliers |
| `AdaptiveLaguerreFilter` | `AdaptiveLaguerre` | Ehlers' adaptive Laguerre filter (median-of-normalised-error γ) |
| `GeneralizedDema` | `GD` | Tillson's volume-factor double EMA; `v=1` is DEMA, `v=0` is EMA |
| `HoltWinters` | `HoltWinters` | Holt's linear double exponential smoothing (level + trend) |
LSMA was dropped from the planned set: it already ships as `LinearRegression`
(TA-Lib `LINEARREG`, the rolling least-squares endpoint).
The five single-period filters use the generated scalar macro bindings;
`GeneralizedDema` (period, v) and `HoltWinters` (alpha, beta) use hand-written
node/python bindings with the typed wasm macro (precedent `T3` / `Alma`).
Full coverage: core modules with per-branch unit tests (100% intent), mod/lib
catalogue, FAMILIES group + assert, README + docs counters, CHANGELOG, all three
bindings (regenerated `index.d.ts` / `index.js`), fuzz drivers, and the
python/node test registries.
Local verification: `cargo test -p wickra-core` (lib 3255 + doc 361),
`cargo clippy --workspace --all-targets --all-features -D warnings` clean,
node `npm run build && npm test` (478), python `pytest` (791).
Adds 19 streaming indicators so an external trading-bot feature extractor can replace its hand-built features with native, batch/streaming-equivalent ones. Each is a real gap (verified against the existing catalogue), production-only, with full Python/Node/WASM bindings, fuzz drivers, and tests. Five commits, one per family group; counter 377 -> 396.
## What's added
**Price Statistics (6)** — `LogReturn`, `RealizedVolatility` (raw quadratic variation, the un-annualised counterpart to `HistoricalVolatility`), `RollingQuantile`, `RollingIqr`, `RollingPercentileRank`, `SpreadAr1Coefficient` (pairwise AR(1) rho of the spread; complements `OuHalfLife`).
**Price Action (4)** — `CloseVsOpen`, `BodySizePct`, `WickRatio`, `HighLowRange` (stateless per-bar OHLC transforms).
**Regime / Trend / Jump labels (3)** — `TrendLabel` (sign of the rolling OLS slope), `JumpIndicator` (return outliers vs trailing volatility, measured as deviation from the trailing mean so steady drift is not flagged), `RegimeLabel` (volatility-quantile regime split).
**Risk / Performance (2)** — `WinRate`, `Expectancy` (R-multiple).
**Microstructure (4)** — `OrderFlowImbalance` (Cont-Kukanov-Stoikov OFI), `Vpin`, `AmihudIlliquidity`, `RollMeasure`. These reuse the existing `OrderBook` / `Trade` inputs (no new input type).
## Intentionally NOT added (already present, would be duplicates)
- **Population skew / kurtosis** — `skewness.rs` / `kurtosis.rs` are already population moments (divisor n).
- **Hurst R/S** — `hurst_exponent.rs` already uses rescaled-range (R/S) analysis.
- **Queue Imbalance** — exactly `OrderBookImbalanceTop1` ((bidSize - askSize) / (bidSize + askSize)).
## Verification
`cargo test -p wickra-core` (lib 3187 + doc 354), `cargo clippy --workspace --all-targets --all-features -D warnings` clean, node `npm run build && npm test` (471), python `pytest` (784). Counter consistent across `mod.rs`, lib block, README, and docs/README at 396.
kingchenc