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>

tests/test_heaven_realtime.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 import http.client
 import json
 import unittest
+from datetime import datetime
 from unittest.mock import MagicMock, patch
 
 from backend.data.realtime import WebRealtimeAggregator
@@ -377,6 +378,43 @@ class RealtimeAggregatorTests(unittest.TestCase):
         self.assertEqual(rows[0]["quote_time"][:10], "2026-07-20")
         self.assertAlmostEqual(rows[0]["amount_billion"], 12946.52)
 
+    @patch.object(WebRealtimeAggregator, "_get_json")
+    def test_eastmoney_market_quotes_normalize_and_keep_expected_date(self, get_json: MagicMock):
+        epoch = datetime(2026, 7, 20, 10, 5).timestamp()
+        rows = []
+        for index in range(200):
+            sz = index < 100
+            rows.append(
+                {
+                    "f12": f"{index:06d}" if sz else f"{600000 + index - 100:06d}",
+                    "f13": 0 if sz else 1,
+                    "f14": f"股票{index}",
+                    "f2": 11.2,
+                    "f3": 2.0,
+                    "f5": 10,
+                    "f6": 50000000,
+                    "f15": 11.3,
+                    "f16": 11.0,
+                    "f17": 11.1,
+                    "f18": 11.0,
+                    "f124": epoch,
+                }
+            )
+        def fake_get_json(_url, params, referer=""):
+            page = int(params.get("pn") or 1)
+            start = (page - 1) * 100
+            return {"rc": 0, "data": {"total": 200, "diff": rows[start:start + 100]}}
+
+        get_json.side_effect = fake_get_json
+        aggregator = WebRealtimeAggregator()
+        aggregator._response_cache.clear()
+        quotes = aggregator.eastmoney_market_quotes("20260720")
+        self.assertEqual(len(quotes), 200)
+        self.assertEqual(quotes[0]["ts_code"], "000000.SZ")
+        self.assertTrue(quotes[100]["ts_code"].endswith(".SH"))
+        self.assertEqual(quotes[0]["vol"], 1000)
+        self.assertEqual(quotes[0]["quote_date"], "20260720")
+
 
 if __name__ == "__main__":
     unittest.main()