feat: add optional Qveris market data source

README.md

@@ -271,6 +271,13 @@ PostgreSQL migration guidance, see
 [Installation troubleshooting](docs/deployment/INSTALL_TROUBLESHOOTING.md) and the
 [cloud deployment guide](docs/deployment/CLOUD_DEPLOYMENT_EN.md).
 
+### Optional Qveris data source
+
+QuantDinger can use Qveris as an opt-in unified market-data layer while keeping
+the existing market providers as automatic fallbacks. See the
+[Qveris data-source guide](docs/integrations/QVERIS_DATA_SOURCE.md) for setup,
+supported markets, safety behavior, and verification.
+
 ## Production deployment
 
 Validate secrets before starting a production stack:

backend_api_python/app/data_sources/factory.py

@@ -187,27 +187,38 @@ def _create_source(cls, market: str) -> BaseDataSource:
         """创建数据源实例"""
         if market == 'Crypto':
             from app.data_sources.crypto import CryptoDataSource
-            return CryptoDataSource()
+            source = CryptoDataSource()
         elif market == 'CNStock':
             from app.data_sources.cn_stock import CNStockDataSource
-            return CNStockDataSource()
+            source = CNStockDataSource()
         elif market == 'HKStock':
             from app.data_sources.hk_stock import HKStockDataSource
-            return HKStockDataSource()
+            source = HKStockDataSource()
         elif market == 'USStock':
             from app.data_sources.us_stock import USStockDataSource
-            return USStockDataSource()
+            source = USStockDataSource()
         elif market == 'Forex':
             from app.data_sources.forex import ForexDataSource
-            return ForexDataSource()
+            source = ForexDataSource()
         elif market == 'Futures':
             from app.data_sources.futures import FuturesDataSource
-            return FuturesDataSource()
+            source = FuturesDataSource()
         elif market == 'MOEX':
             from app.data_sources.moex import MOEXDataSource
-            return MOEXDataSource()
+            source = MOEXDataSource()
         else:
             raise UnsupportedMarketError(market)
+        return cls._wrap_optional_source(market, source)
+
+    @staticmethod
+    def _wrap_optional_source(market: str, source: BaseDataSource) -> BaseDataSource:
+        """Wrap an existing source with Qveris only when explicitly enabled."""
+        from app.data_sources.qveris import QverisDataSource
+
+        if QverisDataSource.is_enabled_for(market):
+            logger.info("Qveris data source enabled for %s with %s fallback", market, source.name)
+            return QverisDataSource(market, source)
+        return source
 
     @classmethod
     def get_kline(