migration: establish exact preserved app baseline

app/backend/data/providers/__init__.py

@@ -0,0 +1,4 @@
+from .ifind import IfindProvider
+from .tushare import TushareProvider
+
+__all__ = ["IfindProvider", "TushareProvider"]

app/backend/data/providers/ifind.py

@@ -0,0 +1,11 @@
+from __future__ import annotations
+
+from ifind_client import IfindHttpClient
+
+
+class IfindProvider:
+    def __init__(self, client: IfindHttpClient) -> None:
+        self.client = client
+
+    def set_credentials(self, refresh_token: str, access_token: str = "") -> None:
+        self.client.set_credentials(refresh_token, access_token)

app/backend/data/providers/tushare.py

@@ -0,0 +1,18 @@
+from __future__ import annotations
+
+from collections.abc import Callable
+
+from tushare_client import TushareClient
+
+
+class TushareProvider:
+    def __init__(
+        self,
+        token_supplier: Callable[[], str],
+        client_factory: Callable[[str], TushareClient] = TushareClient,
+    ) -> None:
+        self._token_supplier = token_supplier
+        self._client_factory = client_factory
+
+    def client(self) -> TushareClient:
+        return self._client_factory(str(self._token_supplier() or "").strip())