fix卖回VWAP必须落库并覆盖指数占位价，禁止预算反推开仓价。

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

lib/sim/hooks.py

@@ -421,7 +421,11 @@ def _patch_spot_bridge_lib() -> None:
                 if not is_sellable_spot_coin(ex, coin, amt):
                     min_sz = spot_min_sell_sz(ex, coin)
                     return {"ok": False, "msg": f"{coin} 可卖数量过小(低于现货最小 {min_sz:g})"}
-                sell_sz = max(0.0, float(amt) * 0.999)
+                # 平仓卖回(coin_amount=None)一次卖光;限量卖才留粉尘余量
+                if coin_amount is None:
+                    sell_sz = float(amt)
+                else:
+                    sell_sz = max(0.0, float(amt) * 0.999)
                 if sell_sz <= 0 or not is_sellable_spot_coin(ex, coin, sell_sz):
                     return {"ok": False, "msg": f"{coin} 可卖数量过小"}
                 pub = _sim_public_exchange(ex)
@@ -445,13 +449,20 @@ def _patch_spot_bridge_lib() -> None:
                     notify_instance_balance_changed()
                 except Exception:
                     pass
+                recovered = result.get("usdt_recovered")
+                if recovered is None and result.get("fill_px") is not None:
+                    try:
+                        recovered = round(float(sell_sz) * float(result.get("fill_px")), 8)
+                    except (TypeError, ValueError):
+                        recovered = None
                 return {
                     "ok": True,
                     "inst_id": result.get("inst_id") or "",
                     "ord_id": f"sim-spot-sell-{result.get('fill_px') or 0}",
                     "coin_sold": float(sell_sz),
+                    "fill_px": result.get("fill_px"),
                     "sim": True,
-                    "usdt_recovered": result.get("usdt_recovered"),
+                    "usdt_recovered": recovered,
                     "data": {"sCode": "0", "sMsg": "sim filled"},
                 }
         except Exception as e: