feat(bridge): bridge稳定性完善—自动重连miniQMT+health探活+交易日判断

- xt_gateway: _open_session抽离, reconnect(stop旧trader+重建), is_alive(query探活), _retry_with_reconnect(query/order失败重连重试一次)
- query_account/positions/place_order包重试: 断线(异常/None)→reconnect→重试, broker拒单(order_id<=0)不重连
- bridge /health: is_alive真实探活(5s缓存)+断线后台reconnect(不阻塞), 不再假阳性
- trade_calendar: is_trading_day(周一-周五), /order非交易日加warning(120141提示)
- test_gateway15+test_trade_calendar6=NAS21passed, 回归bridge_client/d4a 10绿
- 修复Issue#4运维发现: miniQMT重启后bridge自动重连(无需手动重启)

sanguo_qmt_bridge/bridge.py

@@ -7,6 +7,8 @@ token 鉴权（auth.py），/health 豁免。
 启动：uvicorn bridge:app --host 127.0.0.1 --port 8765
 """
 import logging
+import threading
+import time
 from contextlib import asynccontextmanager
 from typing import Literal
 
@@ -14,6 +16,7 @@ from fastapi import Depends, FastAPI
 from pydantic import BaseModel, Field
 
 from auth import verify_token
+from trade_calendar import is_trading_day
 from xt_gateway import gateway
 
 logging.basicConfig(
@@ -51,12 +54,44 @@ async def lifespan(_app: FastAPI):
 app = FastAPI(title="sanguo QMT bridge", version="0.1.0", lifespan=lifespan)
 
 
+# ===== /health 探活缓存（避免每次 health 都 query_stock_asset）=====
+_PROBE_CACHE_SECONDS = 5.0
+_last_probe_time: float = 0.0
+_last_probe_alive: bool = False
+
+
+def _probe_alive() -> bool:
+    """探活 miniQMT 真实连接（5 秒缓存）。
+
+    缓存过期时调 gateway.is_alive()（query_stock_asset 探活）；
+    探活失败且 gateway 自认已连接 → 后台触发 reconnect（不阻塞 health 响应）。
+    """
+    global _last_probe_time, _last_probe_alive
+    now = time.monotonic()
+    if now - _last_probe_time < _PROBE_CACHE_SECONDS:
+        return _last_probe_alive
+
+    alive = gateway.is_alive()
+    _last_probe_time = now
+    _last_probe_alive = alive
+
+    if not alive and gateway.connected:
+        # _connected 假阳性（miniQMT 可能重启），后台重连不阻塞响应
+        threading.Thread(target=gateway.reconnect, daemon=True).start()
+
+    return alive
+
+
 # ===== 接口 =====
 
 @app.get("/health")
 async def health() -> dict:
-    """健康检查（无需鉴权，供 frpc/Caddy 探活）。"""
-    return {"status": "ok", "miniqmt_connected": gateway.connected}
+    """健康检查（无需鉴权，供 frpc/Caddy 探活）。
+
+    miniqmt_connected 调 gateway.is_alive() 真实探活（5 秒缓存），
+    不再依赖可能假阳性的 _connected 标志。
+    """
+    return {"status": "ok", "miniqmt_connected": _probe_alive()}
 
 
 @app.post("/order", dependencies=[Depends(verify_token)])
@@ -86,7 +121,10 @@ async def place_order(req: OrderRequest) -> dict:
     if order_id <= 0:
         return {"ok": False, "error": f"报单失败 order_id={order_id}"}
     logger.info("下单成功 order_id=%s code=%s action=%s", order_id, req.code, req.action)
-    return {"ok": True, "order_id": order_id}
+    result: dict = {"ok": True, "order_id": order_id}
+    if not is_trading_day():
+        result["warning"] = "非交易日，miniQMT 可能拒绝(120141)"
+    return result
 
 
 @app.get("/account", dependencies=[Depends(verify_token)])