feat: Implement session management with middleware and update authentication flow

main.py

@@ -2,8 +2,10 @@ from typing import Awaitable, Callable
 
 from fastapi import FastAPI, Request, Response
 from fastapi.staticfiles import StaticFiles
-from middleware.validation import validate_json
+
 from config.database import Base, engine
+from middleware.auth_session import AuthSessionMiddleware
+from middleware.validation import validate_json
 from models import (
     FinancialInput,
     Project,
@@ -20,6 +22,8 @@ Base.metadata.create_all(bind=engine)
 
 app = FastAPI()
 
+app.add_middleware(AuthSessionMiddleware)
+
 
 @app.middleware("http")
 async def json_validation(