fix: add missing is_ready method to QdrantService to prevent AttributeError during chat stream retrieval

src/services/qdrant_service.py

@@ -98,6 +98,9 @@ class QdrantService:
     ) -> List[Any]:
         """Hybrid search with metadata filtering."""
         
+        if not self.vectorstore:
+            return []
+            
         from qdrant_client.http import models as rest
         
         filter_conditions = []
@@ -120,6 +123,10 @@ class QdrantService:
             logger.error(f"Qdrant search failed: {e}")
             return []
 
+    def is_ready(self) -> bool:
+        """Check if the vector store is initialized and ready."""
+        return self.vectorstore is not None
+
     def as_retriever(self, k: int = 5, metadata_filters: Dict[str, Any] = None):
         """Return a LangChain retriever interface with dynamic filters."""
         from qdrant_client.http import models as rest