fix(HEL-494): 网站市场客户端改为纯中枢 Facade，并迁移 iFinD 凭据到中枢

生产 gateway 不再读取 Tushare token 或实例化 TushareProvider/TushareClient；问财凭据经带鉴权的中枢接口加密入库，避免发版后 iFinD 未配置。

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

tests/test_data_gateway.py

@@ -35,21 +35,23 @@ class DataGatewayTests(unittest.TestCase):
         with self.assertRaises(DataPolicyError):
             policy.assert_allowed("market.level2", "unresolved", "display")
 
-    def test_gateway_uses_live_token_supplier_and_hub_proxies(self) -> None:
-        token = {"value": "first"}
+    def test_gateway_uses_hub_facade_and_proxies(self) -> None:
         gateway = build_data_gateway(
             {"ifind_refresh_token": "refresh", "ifind_access_token": "access"},
-            lambda: token["value"],
+            lambda: "must-not-be-used",
         )
-        self.assertEqual(gateway.tushare().token, "first")
-        token["value"] = "second"
-        self.assertEqual(gateway.tushare().token, "second")
+        client = gateway.tushare()
+        self.assertEqual(client.token, "datahub")
+        self.assertIsNone(client.realtime_aggregator)
+        self.assertFalse(hasattr(client, "_legacy"))
         self.assertIs(gateway.ifind, gateway.ifind_provider.client)
         self.assertIs(gateway.chart_data.datahub, gateway.datahub)
         self.assertIsNone(gateway.chart_data.ifind)
+        from backend.data.datahub.bridge import DatahubAwareTushareClient
         from backend.data.datahub.ifind_proxy import HubIfindProxy
         from backend.data.datahub.realtime_proxy import HubRealtimeProxy
 
+        self.assertIsInstance(client, DatahubAwareTushareClient)
         self.assertIsInstance(gateway.ifind, HubIfindProxy)
         self.assertIsInstance(gateway.realtime_observer, HubRealtimeProxy)
 
@@ -70,7 +72,6 @@ class DataGatewayTests(unittest.TestCase):
             "IfindProvider": {"backend/data/gateway.py"},
             "MarketChartClient": {"backend/data/gateway.py"},
             "TushareClient": {"backend/features/market/service.py"},
-            "TushareProvider": {"backend/data/gateway.py"},
             "DatahubClient": {"backend/data/gateway.py"},
             "DatahubAwareTushareClient": {"backend/data/gateway.py"},
             "DatahubBridge": {"backend/data/gateway.py"},
@@ -82,6 +83,7 @@ class DataGatewayTests(unittest.TestCase):
             "IfindHttpClient": set(),
             "EastmoneyChartClient": set(),
             "WebRealtimeAggregator": set(),
+            "TushareProvider": set(),
         }
         found_forbidden = {name: set() for name in forbidden}
         for path in (root / "backend").rglob("*.py"):