feat: derivatives funding & open-interest indicators (part 1 of 3) (#126)

* feat(derivatives): DerivativesTick input type + InvalidDerivatives error

* feat(derivatives): FundingRate indicator (core)

* feat(derivatives): FundingRateMean indicator (core)

* feat(derivatives): FundingRateZScore indicator (core)

* feat(derivatives): FundingBasis indicator (core)

* feat(derivatives): OpenInterestDelta indicator (core)

* feat(derivatives): Python, Node and WASM bindings for funding & OI-delta indicators

* test(derivatives): Python and Node tests for funding & OI-delta indicators

* bench(derivatives): synthetic-tick bench + derivatives fuzz target

* docs(derivatives): README family row + counter 232->237, CHANGELOG entry

bindings/node/index.d.ts

@@ -2319,6 +2319,51 @@ export declare class Footprint {
   isReady(): boolean
   warmupPeriod(): number
 }
+export type FundingRateNode = FundingRate
+export declare class FundingRate {
+  constructor()
+  update(fundingRate: number): number | null
+  batch(fundingRate: Array<number>): Array<number>
+  reset(): void
+  isReady(): boolean
+  warmupPeriod(): number
+}
+export type FundingRateMeanNode = FundingRateMean
+export declare class FundingRateMean {
+  constructor(window: number)
+  update(fundingRate: number): number | null
+  batch(fundingRate: Array<number>): Array<number>
+  reset(): void
+  isReady(): boolean
+  warmupPeriod(): number
+}
+export type FundingRateZScoreNode = FundingRateZScore
+export declare class FundingRateZScore {
+  constructor(window: number)
+  update(fundingRate: number): number | null
+  batch(fundingRate: Array<number>): Array<number>
+  reset(): void
+  isReady(): boolean
+  warmupPeriod(): number
+}
+export type FundingBasisNode = FundingBasis
+export declare class FundingBasis {
+  constructor()
+  update(markPrice: number, indexPrice: number): number | null
+  batch(markPrice: Array<number>, indexPrice: Array<number>): Array<number>
+  reset(): void
+  isReady(): boolean
+  warmupPeriod(): number
+}
+export type OpenInterestDeltaNode = OpenInterestDelta
+export declare class OpenInterestDelta {
+  constructor()
+  update(openInterest: number): number | null
+  batch(openInterest: Array<number>): Array<number>
+  reset(): void
+  isReady(): boolean
+  warmupPeriod(): number
+}
 export type SharpeRatioNode = SharpeRatio
 export declare class SharpeRatio {
   constructor(period: number, riskFree: number)