fix(HEL-207): 收盘后改走日线，禁止误调 rt_k，回退旧快照记失败

将实时窗口与调度窗口统一到 15:05；盘后优先日线并补关闭盘后同步；沿用旧快照时 sync/job 记 failed。

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: multica-agent <github@multica.ai>

backend/data/providers/tushare_dashboard.py

@@ -26,18 +26,8 @@ class DashboardMixin:
             )
 
         daily = self._load_daily(trade_date)
-        if (
-            not daily
-            and requested_date == datetime.now().astimezone().strftime("%Y%m%d")
-            and trade_date == requested_date
-            and datetime.now().astimezone().time().replace(tzinfo=None) >= dt_time(9, 15)
-        ):
-            return self._realtime_dashboard(
-                requested_date,
-                trade_date,
-                previous_trade_date,
-            )
         if not daily:
+            # 15:05 后只走日线；日线未就绪时不得回退调用无权限的 rt_k。
             raise TushareError(f"No daily data returned for {trade_date}")
 
         notices: list[str] = []
@@ -96,13 +86,13 @@ class DashboardMixin:
 
     @staticmethod
     def should_use_realtime(requested_date: str, trade_date: str) -> bool:
-        """Use rt_k for today's open market until end-of-day datasets settle."""
+        """Use rt_k only inside the intraday window; 15:05+ must use daily bars."""
         now = datetime.now().astimezone()
         today = now.strftime("%Y%m%d")
         return (
             requested_date == today
             and trade_date == today
-            and dt_time(9, 15) <= now.time().replace(tzinfo=None) < dt_time(16, 30)
+            and dt_time(9, 15) <= now.time().replace(tzinfo=None) < dt_time(15, 5)
         )
 
     def _realtime_dashboard(