持仓导入完成：holding.xls→SQLite+portfolio.json全同步

1. 从 ~/stocks/holding.xls 导入25只持仓（14A/11H）
2. 同时写入 portfolio.json + SQLite holdings 表
3. stale_push_wlin 现金来源从 stale_report 改为 portfolio.json
4. portfolio.json 增加 total_assets 字段兼容 stale_detector
5. 导入脚本已规范化为 MoFin/scripts/import_holding_xls.py
   用法：python3 import_holding_xls.py [--cash 金额]
6. 全量策略重评+决策树重建立即执行

Dad下次更新holding.xls后跑：
  cd MoFin && python3 scripts/import_holding_xls.py

data/price_history.json

@@ -108,7 +108,7 @@
       "date": "2026-06-24",
       "high": 88.32,
       "low": 82.78,
-      "close": 82.82
+      "close": 82.79
     }
   ],
   "00700": [
@@ -1284,7 +1284,7 @@
       "date": "2026-06-24",
       "high": 68.8,
       "low": 65.74,
-      "close": 65.87
+      "close": 66.01
     }
   ],
   "300548": [
@@ -2316,7 +2316,7 @@
       "date": "2026-06-24",
       "high": 745.2,
       "low": 660.01,
-      "close": 678.5
+      "close": 679.95
     }
   ],
   "688802": [
@@ -2466,7 +2466,7 @@
       "date": "2026-06-24",
       "high": 5.38,
       "low": 4.86,
-      "close": 5.16
+      "close": 5.0
     }
   ],
   "688630": [
@@ -2610,7 +2610,7 @@
       "date": "2026-06-24",
       "high": 52.43,
       "low": 49.03,
-      "close": 49.38
+      "close": 49.39
     }
   ],
   "002171": [