QUESTION ROUTER

The backend's QuestionRouter in backend/app/services/question_router.py classifies questions and routes queries to DuckDB SQL backend or Qdrant semantic search. It lazily initializes QdrantService to avoid startup delays, managing structured, textual, and hybrid query paths. It works with TextToSQLService and DuckDBService for SQL generation and execution, and handles query classification and routing within the API layer. QdrantService initialization was changed to lazy loading in the QuestionRouter to prevent startup timeouts QuestionRouter depends on Qdrant, but now falls back gracefully if Qdrant is unavailable Question router routes textual queries to Qdrant semantic search service. The /ask endpoint uses the Question router to classify and route user questions. The Question router capability is validated by the test_question_router test case.