Extend semi-auto with ITM/ATM/OTM, offset, and 1:4 sizing.

Moneyness and perp:option units are plan-only; OTM enforces leverage >=180.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/tests/test_semi_auto.py

@@ -2,7 +2,13 @@
 
 from __future__ import annotations
 
-from app.strategy.semi_auto import REASON_PERP_NET, REASON_POINTS, check_semi_exits
+from app.strategy.selection import pick_otm_strike
+from app.strategy.semi_auto import (
+    REASON_PERP_NET,
+    REASON_POINTS,
+    check_semi_exits,
+    effective_min_leverage,
+)
 
 
 def test_semi_points_long_needs_net_positive() -> None:
@@ -73,3 +79,22 @@ def test_semi_not_yet() -> None:
         risk_k=1,
     )
     assert d.should_close is False
+
+
+def test_otm_leverage_floor() -> None:
+    assert effective_min_leverage("otm", 100) == 180
+    assert effective_min_leverage("otm", 200) == 200
+    assert effective_min_leverage("itm", 100) == 100
+
+
+def test_pick_otm_within_offset() -> None:
+    strikes = [1800.0, 1825.0, 1850.0, 1875.0]
+    # Call 虚值：标的 1830 → 1850（20点）在 25 内；1875 超
+    k = pick_otm_strike(strikes, 1830, option_side="call", max_offset=25)
+    assert k == 1850.0
+    assert (
+        pick_otm_strike(strikes, 1830, option_side="call", max_offset=15) is None
+    )
+    # Put 虚值
+    k2 = pick_otm_strike(strikes, 1830, option_side="put", max_offset=30)
+    assert k2 == 1825.0