半手补整阈值50%→90%，防止现金严重不足却标🛒

修正前：长飞光纤预算60K只有1手112K的一半，却因为
budget > lot_cost*0.5 的规则被凑成1手，标了🛒
修正后：只有预算够90%以上才补整1手
实际影响：长飞光纤现在标⚠️而不是🛒

data/price_history.json

@@ -107,8 +107,8 @@
     {
       "date": "2026-06-24",
       "high": 88.32,
-      "low": 82.89,
-      "close": 82.9
+      "low": 82.83,
+      "close": 82.85
     }
   ],
   "00700": [
@@ -1284,7 +1284,7 @@
       "date": "2026-06-24",
       "high": 68.8,
       "low": 65.92,
-      "close": 66.08
+      "close": 66.14
     }
   ],
   "300548": [
@@ -2316,7 +2316,7 @@
       "date": "2026-06-24",
       "high": 745.2,
       "low": 660.01,
-      "close": 679.11
+      "close": 678.1
     }
   ],
   "688802": [
@@ -2466,7 +2466,7 @@
       "date": "2026-06-24",
       "high": 5.38,
       "low": 4.86,
-      "close": 4.91
+      "close": 4.92
     }
   ],
   "688630": [