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>

recommend_store.py

@@ -2,6 +2,7 @@
 from __future__ import annotations
 
 import json
+import math
 from datetime import datetime
 from typing import Callable, Optional
 
@@ -26,6 +27,50 @@ def filter_affordable_recommendations(rows: list[dict]) -> list[dict]:
     return [r for r in rows if r.get("status") in ("ok", "margin_ok")]
 
 
+def rows_missing_max_lots(rows: list[dict]) -> bool:
+    """缓存是否为旧版（缺少最大手数字段）。"""
+    if not rows:
+        return False
+    return any("max_lots" not in r for r in rows)
+
+
+def enrich_recommend_rows(
+    rows: list[dict],
+    capital: float,
+    *,
+    max_margin_pct: float = 30.0,
+) -> list[dict]:
+    """用当前权益与保证金比例补算最大可开手数（兼容旧缓存）。"""
+    cap = float(capital or 0)
+    pct = max(1.0, min(100.0, float(max_margin_pct or 30.0)))
+    budget = cap * pct / 100.0 if cap > 0 else 0.0
+    enriched: list[dict] = []
+    for raw in rows:
+        row = dict(raw)
+        try:
+            margin_one = float(row.get("margin_one_lot") or 0)
+        except (TypeError, ValueError):
+            margin_one = 0.0
+        if margin_one > 0 and budget > 0:
+            lots = int(math.floor(budget / margin_one))
+        else:
+            try:
+                lots = int(row.get("max_lots") or row.get("recommended_lots") or 0)
+            except (TypeError, ValueError):
+                lots = 0
+        row["max_lots"] = lots
+        row.pop("recommended_lots", None)
+        row["margin_budget"] = round(budget, 2)
+        row["max_margin_pct"] = pct
+        status = row.get("status") or ""
+        if lots >= 1 and status in ("ok", "margin_ok"):
+            row["status_label"] = (
+                f"最大 {lots} 手" if status == "ok" else f"最大 {lots} 手·止损偏宽"
+            )
+        enriched.append(row)
+    return enriched
+
+
 def refresh_recommend_cache(
     conn,
     capital: float,
@@ -85,8 +130,21 @@ def load_recommend_cache(conn) -> dict:
     }
 
 
-def recommend_payload(conn, *, live_capital: float) -> dict:
+def recommend_payload(
+    conn,
+    *,
+    live_capital: float,
+    max_margin_pct: float = 30.0,
+) -> dict:
     """读取缓存并附带当前权益（展示用，可能与缓存计算时不同）。"""
     payload = load_recommend_cache(conn)
-    payload["capital"] = float(live_capital or 0)
+    cap = float(live_capital or 0)
+    pct = max(1.0, min(100.0, float(max_margin_pct or 30.0)))
+    payload["capital"] = cap
+    payload["max_margin_pct"] = pct
+    payload["rows"] = enrich_recommend_rows(
+        payload.get("rows") or [],
+        cap,
+        max_margin_pct=pct,
+    )
     return payload