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/features/market/service.py

@@ -175,6 +175,30 @@ class MarketServiceMixin:
         age_seconds = (now - updated_at.astimezone(now.tzinfo)).total_seconds()
         return age_seconds >= 8
 
+    def _closing_snapshot_due(
+        self,
+        normalized_date: str,
+        snapshot: dict[str, Any],
+    ) -> bool:
+        """After 15:05, keep requesting daily bars until today's EOD snapshot exists."""
+        if not self.configured or normalized_date != date.today().strftime("%Y%m%d"):
+            return False
+        now = datetime.now().astimezone()
+        if now.weekday() >= 5:
+            return False
+        local_time = now.time().replace(tzinfo=None)
+        if local_time < datetime.strptime("15:05", "%H:%M").time():
+            return False
+        meta = snapshot.get("meta") or {}
+        snapshot_trade_date = str(meta.get("trade_date") or "").replace("-", "")
+        if (
+            snapshot_trade_date == normalized_date
+            and not meta.get("realtime")
+            and not meta.get("carried_forward")
+        ):
+            return False
+        return True
+
     def sync_dashboard(self, trade_date: str) -> dict[str, Any]:
         normalized_date = normalize_date(trade_date)
         source = "tushare"
@@ -219,9 +243,15 @@ class MarketServiceMixin:
                         fallback, normalized_date, f"最新行情暂不可用，沿用最近收盘快照：{exc}"
                     )
                     self.database.finish_sync(
-                        sync_id, "fallback", self._record_count(carried), str(exc), "tushare"
+                        sync_id, "failed", self._record_count(carried), str(exc), "tushare"
                     )
-                    return self._apply_reason_overrides(self._with_storage(carried, cached=True))
+                    result = self._apply_reason_overrides(
+                        self._with_storage(carried, cached=True)
+                    )
+                    # 页面仍可读到沿用快照；后台任务通过顶层 status=failed 记失败。
+                    result["status"] = "failed"
+                    result["error"] = str(exc)
+                    return result
                 self.database.finish_sync(sync_id, "failed", message=str(exc))
                 raise ValueError("暂无可用的真实行情快照，请等待后台完成首次同步。") from exc
             except Exception as exc: