Add one-expiry-per-day open rhythm gate (default on).

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

backend/tests/test_p1_p2_rules.py

@@ -3,7 +3,12 @@ from zoneinfo import ZoneInfo
 
 from app.sim.liquidity import bid_mark_ok
 from app.sim.pricing import option_fill, perp_fill
-from app.strategy.clock import can_open_new, window_key
+from app.strategy.clock import (
+    can_open_new,
+    expiry_blocked_by_one_per_day,
+    used_expiry_ymds_for_day,
+    window_key,
+)
 from app.strategy.exits import check_expiry_close, check_exits
 from app.strategy.signal import decide
 
@@ -142,6 +147,30 @@ def test_window_weekend_skip() -> None:
     assert window_key(fri) == "20260724"
 
 
+def test_one_expiry_per_day(tmp_path, monkeypatch) -> None:
+    monkeypatch.setenv("MODE", "SIM")
+    from app.models.db import Database
+
+    db = Database(tmp_path / "one_exp.db")
+    day = datetime(2026, 8, 1, 12, 0, tzinfo=_SH)
+    with db._lock:
+        db._conn.execute(
+            """INSERT INTO groups(group_id, status, expiry_ymd, open_at_ms)
+               VALUES ('G-20260801-01','closed','260802',1)"""
+        )
+        db._conn.execute(
+            """INSERT INTO groups(group_id, status, expiry_ymd, open_at_ms)
+               VALUES ('G-20260731-01','closed','260801',1)"""
+        )
+        db._conn.commit()
+    used = used_expiry_ymds_for_day(db, day)
+    assert used == {"260802"}
+    assert expiry_blocked_by_one_per_day("260802", used, enabled=True) is True
+    assert expiry_blocked_by_one_per_day("260803", used, enabled=True) is False
+    assert expiry_blocked_by_one_per_day("260802", used, enabled=False) is False
+    db.close()
+
+
 def test_bid_mark_deviation_30pct() -> None:
     # |7-10|/10 = 30% → 允许（≤30%）
     ok, _ = bid_mark_ok(bid=7.0, mark=10.0, max_dev_pct=30)