feat: add 5-day reversal strategy

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tests/test_reversal.py

@@ -0,0 +1,21 @@
+import pytest
+from backtest.config import BacktestConfig
+from backtest.runner import BacktestRunner
+from strategies.reversal import FiveDayReversal
+
+
+def test_reversal_smoke():
+    """Smoke test: run a minimal reversal backtest and check results exist."""
+    config = BacktestConfig(
+        symbols=["sh600000"],
+        start_date="2024-01-01",
+        end_date="2024-03-31",
+        initial_cash=100_000,
+    )
+    runner = BacktestRunner(config)
+    results = runner.run(FiveDayReversal)
+    assert results is not None
+    assert len(results) == 1
+    # Check analyzers exist
+    sharpe = results[0].analyzers.sharpe.get_analysis()
+    assert "sharperatio" in sharpe