修复持仓监控页长时间空白：品种推荐改为异步加载。

页面先渲染三卡片，推荐表并行拉行情，持仓与推荐分别通过 API 加载。

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

product_recommend.py

@@ -1,6 +1,7 @@
 """按账户资金推荐可交易品种（期货核心筛选）。"""
 from __future__ import annotations
 
+from concurrent.futures import ThreadPoolExecutor
 from typing import Callable, Optional
 
 from contract_specs import get_contract_spec
@@ -83,14 +84,16 @@ def list_product_recommendations(
     max_position_pct: float = 50.0,
 ) -> list[dict]:
     """扫描全部品种并排序：推荐 > 可开 > 不足。"""
-    rows = []
-    for p in PRODUCTS:
-        ths = p["ths"]
+
+    def _one(product: dict) -> dict:
+        ths = product["ths"]
         main_code = price_fn(ths)
-        row = assess_product_for_capital(
-            p, capital, main_code, max_position_pct=max_position_pct
+        return assess_product_for_capital(
+            product, capital, main_code, max_position_pct=max_position_pct
         )
-        rows.append(row)
+
+    with ThreadPoolExecutor(max_workers=10) as pool:
+        rows = list(pool.map(_one, PRODUCTS))
     order = {"ok": 0, "margin_ok": 1, "blocked": 2, "no_price": 3}
     rows.sort(key=lambda r: (order.get(r["status"], 9), r.get("min_capital_one_lot") or 1e18))
     return rows