feat: add Alt-Chart Bars (Renko, Kagi, Point & Figure) via a BarBuilder trait (#146)

Introduces a BarBuilder trait for price-driven chart constructors that emit a variable number of bars per candle (deliberately not Indicator). Adds Renko (box-size bricks, 2-box reversal), Kagi (reversal-amount segments) and Point & Figure (box-size X/O columns, N-box reversal) in a new Alt-Chart Bars family, with custom Python/Node/WASM bindings, a dedicated fuzz target, tests and docs. Indicator count 292 -> 295.

bindings/node/index.d.ts

@@ -310,6 +310,21 @@ export interface LiquidationFeaturesValue {
   total: number
   imbalance: number
 }
+export interface RenkoBrickValue {
+  open: number
+  close: number
+  direction: number
+}
+export interface KagiSegmentValue {
+  start: number
+  end: number
+  direction: number
+}
+export interface PnfColumnValue {
+  direction: number
+  high: number
+  low: number
+}
 export type SmaNode = SMA
 export declare class SMA {
   constructor(period: number)
@@ -3022,6 +3037,31 @@ export declare class InformationRatio {
   isReady(): boolean
   warmupPeriod(): number
 }
+export type RenkoBarsNode = RenkoBars
+export declare class RenkoBars {
+  constructor(boxSize: number)
+  update(close: number): Array<RenkoBrickValue>
+  batch(close: Array<number>): Array<RenkoBrickValue>
+  boxSize(): number
+  reset(): void
+}
+export type KagiBarsNode = KagiBars
+export declare class KagiBars {
+  constructor(reversal: number)
+  update(close: number): Array<KagiSegmentValue>
+  batch(close: Array<number>): Array<KagiSegmentValue>
+  reversal(): number
+  reset(): void
+}
+export type PointAndFigureBarsNode = PointAndFigureBars
+export declare class PointAndFigureBars {
+  constructor(boxSize: number, reversal: number)
+  update(close: number): Array<PnfColumnValue>
+  batch(close: Array<number>): Array<PnfColumnValue>
+  boxSize(): number
+  reversal(): number
+  reset(): void
+}
 export type AlphaNode = Alpha
 export declare class Alpha {
   constructor(period: number, riskFree: number)