全数据路径审计修复：price_monitor HK股价不再转CNY

审计发现(2026-07-03 15:00 systematic audit):
1. price_monitor 港股仍转 CNY (line 255, 306) → 改为存 HKD 原值, currency=HKD
2. strategy_lifecycle 质量门禁检查 currency=CNY (line 88-91) → 改为接受 HKD/CNY
3. strategy_lifecycle 新建策略写 currency='CNY' (line 2299) → 改为按代码判断 HKD/CNY
4. stale_push_wlin 两处直接 json.load(open(decisions.json)) → 改为 read_decisions()
5. stale_push_wlin 直接 json.load(open(portfolio.json)) → 改为 read_portfolio()
6. DB holdings/holding_strategies: 8只HK股currency从CNY改为HKD
7. calc_total_mv 增加港股HKD→CNY汇兑计算

验证:
- 建滔 84.45 HKD 浮亏-4.3%（不是-24%）
- 现金 132,121.93 总资产 953,295
- 所有8只HK股DB正确标记HKD
- price_monitor已重启，下个tick用新逻辑写HKD原值
- stale_push_wlin已换用mo_data读DB

data/price_events.json

@@ -9149,6 +9149,26 @@
       "event_label": "",
       "timestamp": "2026-07-03T14:36:05.312970",
       "date": "2026-07-03"
+    },
+    {
+      "code": "300548",
+      "name": "长芯博创",
+      "event_type": "stop_loss",
+      "price": 221.27,
+      "trigger_value": "221.38",
+      "event_label": "",
+      "timestamp": "2026-07-03T14:52:17.930474",
+      "date": "2026-07-03"
+    },
+    {
+      "code": "688981",
+      "name": "中芯国际",
+      "event_type": "stop_loss",
+      "price": 140.59,
+      "trigger_value": "140.94",
+      "event_label": "",
+      "timestamp": "2026-07-03T14:52:19.831851",
+      "date": "2026-07-03"
     }
   ]
 }