Add demo trading executor and analysis scheduling (plan 3 C4)

- Executor reconciles each symbol to its desired orders: journaled ap{id}
  client ids, reduce-only quantity stop placed before entries, make-before-
  break stop moves, breakeven after TP1, orphan cancel, -2021 market close
- Plan lifecycle: proposed plans are adopted only if the position is
  unchanged; holding-mode plans may only tighten the stop
- Program rules: time stop, short-term invalidation close, long-term 4h
  review, reevaluate conditions, takeover of unmanaged positions
- Trigger and routine analysis scheduling with a 10 min gap, daily cap and
  bounded retries
- Plan endpoint and plan status, fills and countdowns on the trading page

backend/src/alphapulse/trading/engine.py

@@ -1,4 +1,4 @@
-"""模拟盘交易进程：同步账户快照、调度分析。
+"""模拟盘交易进程：同步账户快照、执行器对账、调度分析。
 
 用法：python -m alphapulse.trading.engine
 """
@@ -12,6 +12,8 @@ from sqlalchemy import select, update
 from alphapulse.core.db import SessionLocal
 from alphapulse.models import TradingAnalysis, TradingSymbol
 from alphapulse.trading.analyst import run_analysis
+from alphapulse.trading.executor import executor_loop
+from alphapulse.trading.schedule import routine_requests
 from alphapulse.trading.snapshot import snapshot_loop
 
 logger = logging.getLogger("alphapulse.trading.engine")
@@ -57,6 +59,7 @@ async def analysis_loop() -> None:
                     del tasks[symbol]
                     if not task.cancelled() and task.exception():
                         logger.error("%s 分析任务异常退出", symbol, exc_info=task.exception())
+            await routine_requests()
             free = MAX_CONCURRENT_ANALYSES - len(tasks)
             if free > 0:
                 for symbol, reasons in await claim_requests(free, set(tasks)):
@@ -69,6 +72,7 @@ async def analysis_loop() -> None:
 async def main() -> None:
     async with asyncio.TaskGroup() as tg:
         tg.create_task(snapshot_loop())
+        tg.create_task(executor_loop())
         tg.create_task(analysis_loop())