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

price_monitor.py

@@ -250,14 +250,12 @@ def refresh_data_prices():
         if s['code'] in prices:
             price, _, change_pct = prices[s['code']]
             if price > 0:
-                # 港股：API返回HKD，需转CNY。系统统一存CNY标价
-                if is_hk_stock(s['code']):
-                    price = round(price * HK_RATE, 2)
+                # 港股API返回HKD，直接存HKD原值。港股标价存HKD，A股标价存CNY
                 old = s.get('price') or 0
                 if abs(old - price) > 0.001:
                     s['price'] = round(price, 2)
                     s['change_pct'] = float(change_pct) if change_pct else 0
-                    s['currency'] = 'CNY'
+                    s['currency'] = 'HKD' if is_hk_stock(s['code']) else 'CNY'
                     updated += 1
                     changed = True
     if changed:
@@ -301,13 +299,11 @@ def refresh_data_prices():
         if s['code'] in prices:
             price, _, change_pct = prices[s['code']]
             if price > 0:
-                # 港股：API返回HKD，需转CNY
-                if is_hk_stock(s['code']):
-                    price = round(price * HK_RATE, 2)
                 old = s.get('price') or 0
                 if abs(old - price) > 0.001:
                     s['price'] = round(price, 2)
                     s['change_pct'] = float(change_pct) if change_pct else 0
+                    s['currency'] = 'HKD' if is_hk_stock(s['code']) else 'CNY'
                     updated += 1
                     changed = True
     if changed: