feat: DB-first architecture with lock-safe writes

- price_monitor: writes live prices to both JSON and mofin.db (holdings + live_prices + portfolio_summary)
- mofin_db: added execute_with_retry/commit_with_retry with exponential backoff on 'database is locked'
- mofin_db: increased timeout 5s->15s, added PRAGMA busy_timeout=15000
- price_monitor retry loop: fixed break-before-if-ok bug (was not retrying on write failure)
- DB connection: WAL mode + retry decorator for all write operations
- cash sync: preserves DB authoritative cash (JSON cash not pushed to DB)

This is the DB-first version. JSON writes remain for dashboard compatibility.
Next step: remove JSON writes entirely for full DB-only architecture.

mo_data.py

@@ -20,15 +20,22 @@ DB_PATH = '/home/hmo/web-dashboard/data/mofin.db'
 
 
 def _get_db():
-    db = sqlite3.connect(DB_PATH)
+    """获取数据库连接（WAL 模式，15秒超时防并发锁）"""
+    db = sqlite3.connect(DB_PATH, timeout=15)
     db.row_factory = sqlite3.Row
+    db.execute("PRAGMA journal_mode=WAL")
+    db.execute("PRAGMA busy_timeout=15000")
     return db
 
 
 # ── portfolio ─────────────────────────────────────────────────────
 
 def read_portfolio():
-    """返回 portfolio.json 等价 dict。纯 DB。"""
+    """返回 portfolio.json 等价 dict。纯 DB。
+    
+    总市值从 holdings 实时计算（shares × price，港股 × 汇率），
+    不信任 portfolio_summary 的存储值，因为可能未及时更新。
+    """
     db = _get_db()
     rows = db.execute(
         "SELECT code, name, shares, cost, price, market_value, "
@@ -46,14 +53,46 @@ def read_portfolio():
 
     db.close()
 
+    # ── 总市值从 holdings 实时计算 ────────────────────
+    cash = float(summary.get('cash', 0) or 0)
+    frozen = float(summary.get('frozen_cash', 0) or 0)
+
+    # 获取港股汇率
+    import subprocess, os as _os
+    rate = 0.865  # 默认值
+    try:
+        hk_rate_py = _os.path.join(_os.path.dirname(_os.path.dirname(__file__)), 'hk_rate.py')
+        if _os.path.exists(hk_rate_py):
+            r = subprocess.run(
+                [_os.path.join(_os.path.dirname(_os.path.dirname(__file__)), 'venv', 'bin', 'python3'),
+                 hk_rate_py, '--rate'],
+                capture_output=True, text=True, timeout=10
+            )
+            if r.returncode == 0 and r.stdout.strip():
+                rate = float(r.stdout.strip())
+    except Exception:
+        pass
+
+    total_mv = 0.0
+    for h in holdings:
+        p = float(h.get('price', 0) or 0)
+        s = float(h.get('shares', 0) or 0)
+        if h.get('currency') == 'HKD' or (len(str(h.get('code',''))) == 5 and str(h.get('code',''))[0] in ('0','1')):
+            total_mv += s * p * rate
+        else:
+            total_mv += s * p
+    total_mv = round(total_mv, 2)
+    total_assets = round(total_mv + cash + frozen, 2)
+    position_pct = round(total_mv / total_assets * 100, 2) if total_assets > 0 else 0
+
     return {
         "holdings": holdings,
-        "total_assets": summary.get("total_assets", 0),
-        "total_mv": summary.get("total_mv", 0),
-        "stock_value": summary.get("stock_value", summary.get("total_mv", 0)),
-        "cash": summary.get("cash", 0),
-        "frozen_cash": summary.get("frozen_cash", 0),
-        "position_pct": summary.get("position_pct", 0),
+        "total_assets": total_assets,
+        "total_mv": total_mv,
+        "stock_value": total_mv,
+        "cash": cash,
+        "frozen_cash": frozen,
+        "position_pct": position_pct,
         "currency": summary.get("currency", "CNY"),
         "updated_at": summary.get("updated_at", ""),
     }