feat(HEL-402): 接通网站首批只读 datahub 并建立双路对比

默认全部读取/影子开关关闭，网站继续走旧 Tushare 链路；开启单项时只替换该类原料并在失败时回旧，问天保持旧路径。

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

backend/data/gateway.py

@@ -3,8 +3,10 @@ from __future__ import annotations
 from collections.abc import Callable
 from dataclasses import dataclass
 from datetime import datetime
+from typing import Any
 
 from backend.data.contracts import DataUsage
+from backend.data.datahub import DatahubAwareTushareClient, DatahubBridge, DatahubClient, DatahubSettings
 from backend.data.policy import DataSourcePolicy
 from backend.data.providers import IfindProvider, TushareProvider
 from backend.data.quality import DataQualityGate, QualityEvidence, QualityReport
@@ -22,6 +24,7 @@ class DataGateway:
     ifind_provider: IfindProvider
     chart_data: MarketChartClient
     realtime_observer: WebRealtimeAggregator
+    datahub: DatahubBridge
 
     @property
     def ifind(self) -> IfindHttpClient:
@@ -34,7 +37,13 @@ class DataGateway:
     ) -> TushareClient:
         if dataset_id:
             self.policy.assert_allowed(dataset_id, "tushare", usage)
-        return self.tushare_provider.client()
+        return DatahubAwareTushareClient(self.tushare_provider.client(), self.datahub)
+
+    def dataset_status(self, trade_date: str) -> list[dict[str, Any]] | None:
+        return self.datahub.dataset_status(trade_date)
+
+    def batches(self, trade_date: str, dataset: str = "") -> list[dict[str, Any]] | None:
+        return self.datahub.batches(trade_date, dataset)
 
     def assert_source(self, dataset_id: str, provider_id: str, usage: DataUsage) -> None:
         self.policy.assert_allowed(dataset_id, provider_id, usage)
@@ -64,6 +73,7 @@ class DataGateway:
 def build_data_gateway(
     credentials: dict[str, object],
     tushare_token_supplier: Callable[[], str] | None = None,
+    datahub_settings: DatahubSettings | None = None,
 ) -> DataGateway:
     ifind = IfindHttpClient(
         str(credentials.get("ifind_refresh_token") or ""),
@@ -73,6 +83,8 @@ def build_data_gateway(
         lambda: str(credentials.get("tushare_token") or "")
     )
     policy = DataSourcePolicy.load()
+    settings = datahub_settings or DatahubSettings.load(credentials=credentials)
+    datahub_client = DatahubClient(settings)
     return DataGateway(
         policy=policy,
         quality=DataQualityGate.load(policy),
@@ -80,4 +92,5 @@ def build_data_gateway(
         ifind_provider=IfindProvider(ifind),
         chart_data=MarketChartClient(ifind, EastmoneyChartClient()),
         realtime_observer=WebRealtimeAggregator(),
+        datahub=DatahubBridge(settings, datahub_client),
     )