feat: add Pivots & S/R indicators (B11) (#201)

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).

bindings/node/index.d.ts

@@ -239,6 +239,31 @@ export interface ProjectionBandsValue {
   middle: number
   lower: number
 }
+export interface CentralPivotRangeValue {
+  pivot: number
+  tc: number
+  bc: number
+}
+export interface MurreyMathLinesValue {
+  mm8_8: number
+  mm7_8: number
+  mm6_8: number
+  mm5_8: number
+  mm4_8: number
+  mm3_8: number
+  mm2_8: number
+  mm1_8: number
+  mm0_8: number
+}
+export interface AndrewsPitchforkValue {
+  median: number
+  upper: number
+  lower: number
+}
+export interface VolumeWeightedSrValue {
+  support: number
+  resistance: number
+}
 export interface DoubleBollingerValue {
   upperOuter: number
   upperInner: number
@@ -2930,6 +2955,51 @@ export declare class ProjectionBands {
   isReady(): boolean
   warmupPeriod(): number
 }
+export type CentralPivotRangeNode = CentralPivotRange
+export declare class CentralPivotRange {
+  constructor()
+  update(high: number, low: number, close: number): CentralPivotRangeValue | null
+  batch(high: Array<number>, low: Array<number>, close: Array<number>): Array<number>
+  reset(): void
+  isReady(): boolean
+  warmupPeriod(): number
+}
+export type MurreyMathLinesNode = MurreyMathLines
+export declare class MurreyMathLines {
+  constructor(period: number)
+  update(high: number, low: number): MurreyMathLinesValue | null
+  batch(high: Array<number>, low: Array<number>): Array<number>
+  reset(): void
+  isReady(): boolean
+  warmupPeriod(): number
+}
+export type AndrewsPitchforkNode = AndrewsPitchfork
+export declare class AndrewsPitchfork {
+  constructor(strength: number)
+  update(high: number, low: number): AndrewsPitchforkValue | null
+  batch(high: Array<number>, low: Array<number>): Array<number>
+  reset(): void
+  isReady(): boolean
+  warmupPeriod(): number
+}
+export type VolumeWeightedSrNode = VolumeWeightedSr
+export declare class VolumeWeightedSr {
+  constructor(period: number)
+  update(high: number, low: number, volume: number): VolumeWeightedSrValue | null
+  batch(high: Array<number>, low: Array<number>, volume: Array<number>): Array<number>
+  reset(): void
+  isReady(): boolean
+  warmupPeriod(): number
+}
+export type PivotReversalNode = PivotReversal
+export declare class PivotReversal {
+  constructor(left: number, right: number)
+  update(high: number, low: number, close: number): number | null
+  batch(high: Array<number>, low: Array<number>, close: Array<number>): Array<number>
+  reset(): void
+  isReady(): boolean
+  warmupPeriod(): number
+}
 export type DoubleBollingerNode = DoubleBollinger
 export declare class DoubleBollinger {
   constructor(period: number, kInner: number, kOuter: number)