fix(HEL-488): 盘中日K补上今天实时变化的一根

悬浮窗和详情页在 Tushare rt_k / iFinD 不可用时，改用免费实时行情或当日分时生成今日K，收盘后正式日K就绪再无缝替换。

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

tests/test_heaven_realtime.py

@@ -6,7 +6,7 @@ import unittest
 from datetime import datetime
 from unittest.mock import MagicMock, patch
 
-from backend.data.realtime import WebRealtimeAggregator
+from backend.data.realtime import RealtimeAggregateError, WebRealtimeAggregator
 from backend.features.heaven.engine import _market_line_scores, build_manual_market_hexagram
 from server import DashboardService
 from backend.data.providers.tushare_client import (
@@ -415,6 +415,50 @@ class RealtimeAggregatorTests(unittest.TestCase):
         self.assertEqual(quotes[0]["vol"], 1000)
         self.assertEqual(quotes[0]["quote_date"], "20260720")
 
+    @patch.object(WebRealtimeAggregator, "_get_text")
+    def test_tencent_stock_quote_keeps_expected_date(self, get_text: MagicMock):
+        fields = [""] * 38
+        fields[1] = "浦发银行"
+        fields[2] = "600000"
+        fields[3] = "11.20"
+        fields[4] = "11.00"
+        fields[5] = "11.10"
+        fields[6] = "1234"
+        fields[30] = "20260720103000"
+        fields[33] = "11.30"
+        fields[34] = "11.00"
+        fields[37] = "1380"
+        get_text.return_value = (f'v_sh600000="{"~".join(fields)}";', 0)
+
+        quote = WebRealtimeAggregator().tencent_stock_quote("600000", "20260720")
+
+        self.assertEqual(quote["ts_code"], "600000.SH")
+        self.assertEqual(quote["quote_date"], "20260720")
+        self.assertEqual(quote["vol"], 123400)
+        self.assertAlmostEqual(quote["amount"], 13_800_000)
+
+    @patch.object(WebRealtimeAggregator, "_get_json")
+    def test_eastmoney_stock_quote_rejects_stale_date(self, get_json: MagicMock):
+        epoch = datetime(2026, 7, 19, 15, 0).timestamp()
+        get_json.return_value = {
+            "rc": 0,
+            "data": {
+                "f43": 11.2,
+                "f44": 11.3,
+                "f45": 11.0,
+                "f46": 11.1,
+                "f47": 10,
+                "f48": 50000000,
+                "f57": "300750",
+                "f58": "宁德时代",
+                "f60": 11.0,
+                "f86": epoch,
+            },
+        }
+
+        with self.assertRaises(RealtimeAggregateError):
+            WebRealtimeAggregator().eastmoney_stock_quote("300750.SZ", "20260720")
+
 
 if __name__ == "__main__":
     unittest.main()