fix: 品种推荐改为最大手数并补算旧缓存。

- 最大手数 = floor(权益×保证金上限%÷1手保证金)
- 加载与 SSE 推送时实时补算，旧缓存缺字段时自动刷新

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

product_recommend.py

@@ -47,14 +47,14 @@ def assess_product_for_capital(
             "status_label": "暂无行情",
             "min_capital_one_lot": None,
             "margin_one_lot": None,
-            "recommended_lots": 0,
+            "max_lots": 0,
             "risk_one_lot_1pct": None,
         }
 
     margin_one = p * mult * margin_rate
     min_capital = margin_one / (margin_pct / 100.0) if margin_pct > 0 else margin_one
     margin_budget = cap * margin_pct / 100.0 if cap > 0 else 0.0
-    recommended_lots = int(math.floor(margin_budget / margin_one)) if margin_one > 0 and margin_budget > 0 else 0
+    max_lots = int(math.floor(margin_budget / margin_one)) if margin_one > 0 and margin_budget > 0 else 0
     stop_dist = tick * default_stop_ticks
     risk_one_lot = stop_dist * mult
     risk_pct_1lot = (risk_one_lot / cap * 100) if cap > 0 else 999.0
@@ -65,13 +65,13 @@ def assess_product_for_capital(
         fee_ths, p, p, 1.0, open_time="", close_time="", trading_mode=trading_mode,
     )
 
-    can_margin = recommended_lots >= 1
+    can_margin = max_lots >= 1
     can_risk = cap > 0 and risk_one_lot <= cap * 0.01
 
     if can_margin and can_risk:
-        status, label = "ok", f"推荐 {recommended_lots} 手"
+        status, label = "ok", f"最大 {max_lots} 手"
     elif can_margin:
-        status, label = "margin_ok", f"可开 {recommended_lots} 手·止损偏宽"
+        status, label = "margin_ok", f"最大 {max_lots} 手·止损偏宽"
     else:
         status, label = "blocked", "资金不足"
 
@@ -84,7 +84,7 @@ def assess_product_for_capital(
         "tick_size": tick,
         "margin_one_lot": round(margin_one, 2),
         "min_capital_one_lot": round(min_capital, 2),
-        "recommended_lots": recommended_lots,
+        "max_lots": max_lots,
         "margin_budget": round(margin_budget, 2),
         "max_margin_pct": margin_pct,
         "risk_one_lot_1pct": round(risk_one_lot, 2),
@@ -123,5 +123,5 @@ def list_product_recommendations(
     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("recommended_lots") or 0)))
+    rows.sort(key=lambda r: (order.get(r["status"], 9), -(r.get("max_lots") or 0)))
     return rows