feat: TA-Lib candlestick patterns — tasuki-gap/unique-three-river/marubozu-pair/concealing-baby-swallow (part 9 of 9) (#141)

The final batch of the TA-Lib candlestick roadmap. Adds five patterns, each a streaming `Indicator<Input = Candle, Output = f64>` emitting the family's uniform `±1.0 / 0.0` sign convention, fully wired across the Rust core, Python / Node / WASM bindings, fuzz target and reference tests.

- **Tasuki Gap** (`CDLTASUKIGAP`) — a 3-bar continuation: two same-coloured candles gap in the trend direction, then an opposite candle opens within the second body and closes back into the gap without filling it; upside +1, downside -1.
- **Unique Three River** (`CDLUNIQUE3RIVER`) — a 3-bar bullish reversal: a long black candle, a black candle probing a new low with its body inside the first, then a small white candle held below it; bullish +1.
- **Closing Marubozu** (`CDLCLOSINGMARUBOZU`) — a single long-bodied candle with no shadow on the close end; +1 (white, closes at the high) or -1 (black, closes at the low).
- **Opening Marubozu** — a single long-bodied candle with no shadow on the open end; +1 (white, opens at the low) or -1 (black, opens at the high). No direct TA-Lib equivalent — completes the pair with the closing marubozu.
- **Concealing Baby Swallow** (`CDLCONCEALBABYSWALL`) — a rare 4-bar bullish capitulation: two black marubozu, a black candle gapping down with an upper shadow into the second, then a large black candle engulfing it entirely; bullish +1.

Body and shadow thresholds follow the geometric house style (fixed fractions of the bar range) rather than TA-Lib's rolling averages.

Counter 284 → 289 (mod-count == lib counted block; FAMILIES total 279 → 284).

Stacked on #140 (`feat/cdl-gap-methods`); base retargets to `main` as the stack merges down.

bindings/node/index.d.ts

@@ -2570,6 +2570,51 @@ export declare class Takuri {
   isReady(): boolean
   warmupPeriod(): number
 }
+export type ClosingMarubozuNode = ClosingMarubozu
+export declare class ClosingMarubozu {
+  constructor()
+  update(open: number, high: number, low: number, close: number): number | null
+  batch(open: Array<number>, high: Array<number>, low: Array<number>, close: Array<number>): Array<number>
+  reset(): void
+  isReady(): boolean
+  warmupPeriod(): number
+}
+export type OpeningMarubozuNode = OpeningMarubozu
+export declare class OpeningMarubozu {
+  constructor()
+  update(open: number, high: number, low: number, close: number): number | null
+  batch(open: Array<number>, high: Array<number>, low: Array<number>, close: Array<number>): Array<number>
+  reset(): void
+  isReady(): boolean
+  warmupPeriod(): number
+}
+export type TasukiGapNode = TasukiGap
+export declare class TasukiGap {
+  constructor()
+  update(open: number, high: number, low: number, close: number): number | null
+  batch(open: Array<number>, high: Array<number>, low: Array<number>, close: Array<number>): Array<number>
+  reset(): void
+  isReady(): boolean
+  warmupPeriod(): number
+}
+export type UniqueThreeRiverNode = UniqueThreeRiver
+export declare class UniqueThreeRiver {
+  constructor()
+  update(open: number, high: number, low: number, close: number): number | null
+  batch(open: Array<number>, high: Array<number>, low: Array<number>, close: Array<number>): Array<number>
+  reset(): void
+  isReady(): boolean
+  warmupPeriod(): number
+}
+export type ConcealingBabySwallowNode = ConcealingBabySwallow
+export declare class ConcealingBabySwallow {
+  constructor()
+  update(open: number, high: number, low: number, close: number): number | null
+  batch(open: Array<number>, high: Array<number>, low: Array<number>, close: Array<number>): Array<number>
+  reset(): void
+  isReady(): boolean
+  warmupPeriod(): number
+}
 export type OrderBookImbalanceTop1Node = OrderBookImbalanceTop1
 export declare class OrderBookImbalanceTop1 {
   constructor()