Engine: add stop loss integration (fixed & trailing) with tests

tests/risk/stops/test_fixed_stop.py

@@ -0,0 +1,51 @@
+# tests/risk/stops/test_fixed_stop.py
+import sys
+from pathlib import Path
+import pandas as pd
+import pytest
+
+# Añadir raíz del proyecto al path
+sys.path.insert(0, str(Path(__file__).parent.parent.parent.parent))
+
+from src.risk.stops.fixed_stop import FixedStop
+from src.backtest.trade import TradeType
+
+
+def dummy_data():
+    return pd.DataFrame(
+        {"close": [100, 101, 102]},
+        index=pd.date_range("2024-01-01", periods=3, freq="D")
+    )
+
+
+def test_fixed_stop_long():
+    stop = FixedStop(0.02)
+    price = stop.get_stop_price(
+        data=dummy_data(),
+        idx=1,
+        entry_price=100,
+        trade_type=TradeType.LONG
+    )
+    assert price == 98
+
+
+def test_fixed_stop_short():
+    stop = FixedStop(0.02)
+    price = stop.get_stop_price(
+        data=dummy_data(),
+        idx=1,
+        entry_price=100,
+        trade_type=TradeType.SHORT
+    )
+    assert price == 102
+
+
+def test_fixed_stop_invalid_fraction():
+    with pytest.raises(ValueError):
+        FixedStop(0)
+
+    with pytest.raises(ValueError):
+        FixedStop(1)
+
+    with pytest.raises(ValueError):
+        FixedStop(-0.1)