fix(HEL-487): 盘中当天看板在 rt_k 无权限时降级到免费实时源

rt_k 失败、无权限、超时或空结果时改用东财全市场快照，再失败则用腾讯批量行情；两者都失败仍不退回昨天。

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

backend/data/providers/tushare_dashboard.py

@@ -128,7 +128,7 @@ class DashboardMixin:
         )
         if not codes:
             raise TushareError("No active stock codes available for rt_k")
-        quotes = self.query("rt_k", {"ts_code": codes})
+        quotes, quote_source = self._load_realtime_quotes(codes, trade_date)
         if not quotes:
             raise TushareError(f"No realtime data returned for {trade_date}")
 
@@ -186,12 +186,28 @@ class DashboardMixin:
         previous_sectors = _build_sectors(previous_limits)
         now = self._now()
         market_status = _realtime_market_status(now.time().replace(tzinfo=None))
+        if quote_source == "eastmoney_clist":
+            notice = (
+                "盘中行情由东财免费实时快照计算；涨停原因、封板时间和开板次数以盘后榜单校正为准。"
+            )
+            source_name = "eastmoney"
+        elif quote_source == "tencent_qt":
+            notice = (
+                "盘中行情由腾讯免费实时行情计算；涨停原因、封板时间和开板次数以盘后榜单校正为准。"
+            )
+            source_name = "tencent"
+        else:
+            notice = (
+                "盘中行情由 Tushare rt_k 实时计算；涨停原因、封板时间和开板次数以盘后榜单校正为准。"
+            )
+            source_name = "tushare"
         dashboard = {
             "meta": {
                 "requested_date": _display_date(requested_date),
                 "trade_date": _display_date(trade_date),
                 "previous_trade_date": _display_date(previous_trade_date),
-                "source": "tushare",
+                "source": source_name,
+                "quote_source": quote_source,
                 "mode": "realtime",
                 "realtime": True,
                 "market_status": market_status,
@@ -199,7 +215,8 @@ class DashboardMixin:
                 "auto_refresh": False,
                 "quote_count": len(daily),
                 "updated_at": now.isoformat(timespec="seconds"),
-                "notice": "盘中行情由 Tushare rt_k 实时计算；涨停原因、封板时间和开板次数以盘后榜单校正为准。",
+                "notice": notice,
+                "indices": self._free_realtime_indices() if quote_source != "tushare_rt_k" else [],
             },
             "overview": _build_overview(daily, up_rows, down_rows, broken_rows),
             "limits": limits,
@@ -213,6 +230,67 @@ class DashboardMixin:
         }
         return apply_sentiment_to_dashboard(dashboard)
 
+    def _realtime_aggregator(self):
+        aggregator = getattr(self, "realtime_aggregator", None)
+        if aggregator is None:
+            raise TushareError("免费实时源未配置")
+        return aggregator
+
+    def _load_realtime_quotes(
+        self,
+        codes: str,
+        trade_date: str,
+    ) -> tuple[list[dict[str, Any]], str]:
+        rt_error = ""
+        try:
+            quotes = self.query("rt_k", {"ts_code": codes})
+            if quotes:
+                return list(quotes), "tushare_rt_k"
+            rt_error = f"No realtime data returned for {trade_date}"
+        except TushareError as exc:
+            rt_error = str(exc)
+        try:
+            quotes, quote_source = self._free_realtime_quotes(trade_date, codes)
+        except Exception as exc:
+            raise TushareError(
+                f"当天盘中实时行情不可用：rt_k={rt_error}；免费源={exc}"
+            ) from exc
+        if not quotes:
+            raise TushareError(
+                f"当天盘中实时行情不可用：rt_k={rt_error}；免费源=empty"
+            )
+        return quotes, quote_source
+
+    def _free_realtime_quotes(
+        self,
+        trade_date: str,
+        codes: str = "",
+    ) -> tuple[list[dict[str, Any]], str]:
+        aggregator = self._realtime_aggregator()
+        last_error = ""
+        try:
+            quotes = aggregator.eastmoney_market_quotes(expected_date=trade_date)
+            if quotes:
+                return quotes, "eastmoney_clist"
+        except Exception as exc:
+            last_error = str(exc)
+        code_list = [item for item in str(codes or "").split(",") if item]
+        try:
+            quotes = aggregator.tencent_market_quotes(code_list, expected_date=trade_date)
+        except Exception as exc:
+            raise TushareError(
+                f"eastmoney={last_error or 'empty'}；tencent={exc}"
+            ) from exc
+        if not quotes:
+            raise TushareError(f"eastmoney={last_error or 'empty'}；tencent=empty")
+        return quotes, "tencent_qt"
+
+    def _free_realtime_indices(self) -> list[dict[str, Any]]:
+        try:
+            return self._realtime_aggregator().eastmoney_indices()
+        except Exception:
+            return []
+
     def _load_realtime_reference(
         self,
         trade_date: str,