fix(HEL-494): 数据中枢独占调度，主网站不再回退旧接口

主网站只向中枢要业务数据；来源选择、切源、补数全部在中枢内部完成，失败不再走东财/腾讯/Tushare 保底。

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

backend/data/datahub/client.py

@@ -90,6 +90,24 @@ class DatahubClient:
             params["dataset"] = dataset
         return self.get("/v1/batches", params)
 
+    def query_api(self, api_name: str, params: dict[str, Any] | None = None, fields: str = "") -> DatahubResponse:
+        return self.post(
+            "/v1/query",
+            {"api_name": api_name, "params": params or {}, "fields": fields},
+        )
+
+    def sector_quote(self, code: str, date: str = "") -> DatahubResponse:
+        payload: dict[str, Any] = {"code": code}
+        if date:
+            payload["date"] = date
+        return self.get("/v1/sectors/quote", payload)
+
+    def limit_pool(self, trade_date: str = "") -> DatahubResponse:
+        params: dict[str, Any] = {}
+        if trade_date:
+            params["date"] = trade_date
+        return self.get("/v1/limit-pool", params)
+
     def get(self, path: str, params: dict[str, Any] | None = None) -> DatahubResponse:
         if not self.settings.token:
             raise DatahubError("NOT_CONFIGURED", "DATAHUB_TOKEN is not configured")
@@ -118,15 +136,41 @@ class DatahubClient:
                 )
         raise last_error or DatahubError("INTERNAL", "datahub request failed")
 
-    def _request(self, url: str) -> DatahubResponse:
+    def post(self, path: str, body: dict[str, Any] | None = None) -> DatahubResponse:
+        if not self.settings.token:
+            raise DatahubError("NOT_CONFIGURED", "DATAHUB_TOKEN is not configured")
+        url = self.settings.base_url + path
+        attempts = 1 + max(0, self.settings.retries)
+        last_error: DatahubError | None = None
+        payload = json.dumps(body or {}, ensure_ascii=False).encode("utf-8")
+        for attempt in range(attempts):
+            try:
+                return self._request(url, method="POST", data=payload)
+            except DatahubError as exc:
+                last_error = exc
+                if exc.code not in {"TIMEOUT", "UNAVAILABLE"} or attempt + 1 >= attempts:
+                    raise
+                LOGGER.warning(
+                    "datahub retry %s/%s %s",
+                    attempt + 1,
+                    attempts,
+                    redact_text(str(exc), self.settings.secrets()),
+                )
+        raise last_error or DatahubError("INTERNAL", "datahub request failed")
+
+    def _request(self, url: str, method: str = "GET", data: bytes | None = None) -> DatahubResponse:
+        headers = {
+            "Accept": "application/json",
+            "X-Datahub-Token": self.settings.token,
+            "User-Agent": "XiaobaiReviewDatahub/1.0",
+        }
+        if data is not None:
+            headers["Content-Type"] = "application/json"
         request = urllib.request.Request(
             url,
-            headers={
-                "Accept": "application/json",
-                "X-Datahub-Token": self.settings.token,
-                "User-Agent": "XiaobaiReviewDatahub/1.0",
-            },
-            method="GET",
+            data=data,
+            headers=headers,
+            method=method,
         )
         try:
             with self._urlopen(request, timeout=self.settings.timeout_seconds) as response: