Add OKX trading-account USDC auto-swap and lock exit target while in position.

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

backend/app/strategy/risk_sizing.py

@@ -320,12 +320,22 @@ def apply_risk_sizing_to_ledger(
     option_ask: float,
     db: Database | None = None,
 ) -> RiskSizingResult:
-    """计算并写入 perp/option/exit；非以损定仓模式直接 ok 跳过。"""
+    """计算并写入 perp/option/exit；非以损定仓模式直接 ok 跳过。持仓中拒绝改写。"""
     database = db or get_db()
     ledger = Ledger(database)
     if not is_risk_based(ledger):
         return RiskSizingResult(ok=True, detail="manual_sizing_skip")
 
+    # 有活跃仓：本组成场参数已锁定，禁止重算覆盖
+    pos = database.fetchone("SELECT status, group_id FROM positions WHERE id=1")
+    if pos is not None:
+        st = str(pos["status"] or "flat")
+        if st in ("open", "half_open", "option_closed_perp_pending", "opening"):
+            return RiskSizingResult(
+                ok=False,
+                detail="持仓中已锁定本组成交目标与名义，平仓后再自动计算",
+            )
+
     r = compute_risk_sizing(index_px=index_px, option_ask=option_ask, db=database)
     if not r.ok:
         return r