Refactor imports and enhance query functionality with LangGraph integration; update requirements for new dependencies

app/services/openrouter.py

@@ -3,12 +3,13 @@ from typing import List, Optional
 
 import chromadb
 import pandas as pd
-from db.tables import InvestorTable
 from langchain_core.prompts import PromptTemplate
 from langchain_openai import ChatOpenAI
 from pydantic_schemas import Investor, InvestorList
 from settings import settings
 
+from app.db.tables import InvestorTable
+
 # Add these imports for your databases
 # from sqlalchemy.ext.asyncio import AsyncSession
 # from your_vector_db import VectorDBClient