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/python/tests/test_new_indicators.py

@@ -683,6 +683,26 @@ CANDLE_SCALAR = {
         lambda: ta.Takuri(),
         lambda ind, h, l, c, v: ind.batch(c, h, l, c),
     ),
+    "ClosingMarubozu": (
+        lambda: ta.ClosingMarubozu(),
+        lambda ind, h, l, c, v: ind.batch(c, h, l, c),
+    ),
+    "OpeningMarubozu": (
+        lambda: ta.OpeningMarubozu(),
+        lambda ind, h, l, c, v: ind.batch(c, h, l, c),
+    ),
+    "TasukiGap": (
+        lambda: ta.TasukiGap(),
+        lambda ind, h, l, c, v: ind.batch(c, h, l, c),
+    ),
+    "UniqueThreeRiver": (
+        lambda: ta.UniqueThreeRiver(),
+        lambda ind, h, l, c, v: ind.batch(c, h, l, c),
+    ),
+    "ConcealingBabySwallow": (
+        lambda: ta.ConcealingBabySwallow(),
+        lambda ind, h, l, c, v: ind.batch(c, h, l, c),
+    ),
 }
 
 
@@ -2004,6 +2024,38 @@ def test_takuri_reference():
     t = ta.Takuri()
     assert t.update((10.0, 10.05, 7.0, 10.0, 1.0, 0)) == pytest.approx(1.0)
 
+
+def test_closing_marubozu_reference():
+    t = ta.ClosingMarubozu()
+    assert t.update((10.5, 15.0, 10.0, 15.0, 1.0, 0)) == pytest.approx(1.0)
+
+
+def test_opening_marubozu_reference():
+    t = ta.OpeningMarubozu()
+    assert t.update((10.0, 15.0, 10.0, 14.5, 1.0, 0)) == pytest.approx(1.0)
+
+
+def test_tasuki_gap_reference():
+    t = ta.TasukiGap()
+    assert t.update((10.0, 11.2, 9.8, 11.0, 1.0, 0)) == pytest.approx(0.0)
+    assert t.update((12.0, 14.0, 11.9, 13.5, 1.0, 1)) == pytest.approx(0.0)
+    assert t.update((13.0, 13.1, 11.4, 11.5, 1.0, 2)) == pytest.approx(1.0)
+
+
+def test_unique_three_river_reference():
+    t = ta.UniqueThreeRiver()
+    assert t.update((15.0, 15.1, 10.0, 10.5, 1.0, 0)) == pytest.approx(0.0)
+    assert t.update((14.0, 14.1, 9.0, 11.0, 1.0, 1)) == pytest.approx(0.0)
+    assert t.update((10.2, 10.9, 9.5, 10.4, 1.0, 2)) == pytest.approx(1.0)
+
+
+def test_concealing_baby_swallow_reference():
+    t = ta.ConcealingBabySwallow()
+    assert t.update((20.0, 20.1, 14.9, 15.0, 1.0, 0)) == pytest.approx(0.0)
+    assert t.update((16.0, 16.1, 11.9, 12.0, 1.0, 1)) == pytest.approx(0.0)
+    assert t.update((11.0, 13.0, 9.9, 10.0, 1.0, 2)) == pytest.approx(0.0)
+    assert t.update((14.0, 14.1, 8.9, 9.0, 1.0, 3)) == pytest.approx(1.0)
+
 # --- Lifecycle ------------------------------------------------------------