Refactor WebSocket session handling and improve subscription request handling

main.py

@@ -1,6 +1,7 @@
 from contextlib import asynccontextmanager
 from datetime import datetime
 from pathlib import Path
+from typing import Optional
 from uuid import uuid4
 
 import uvicorn
@@ -68,7 +69,7 @@ app = FastAPI(
 @app.websocket("/ws/{user_id}")
 async def websocket_endpoint(websocket: WebSocket, user_id: str):
     """Endpoint pour les connexions WebSocket"""
-    session_id = None
+    session_id = ""
 
     try:
         client_info = ClientInfo(
@@ -104,7 +105,7 @@ async def websocket_endpoint(websocket: WebSocket, user_id: str):
 
 
 # Endpoints REST
-@app.get("/", response_class=HTMLResponse)
+@app.get("/")
 async def root(request: Request):
     # """Page de test pour les connexions WebSocket"""
     # return templates.TemplateResponse(
@@ -117,10 +118,11 @@ async def root(request: Request):
 @app.post("/subscriptions/{session_id}")
 async def add_subscription(
     session_id: str = Depends(validate_session),
-    subscription_request: SubscriptionRequest = None,
+    subscription_request: Optional[SubscriptionRequest] = None,
 ):
     """Ajoute un nouvel abonnement pour une session"""
-    subscription = Subscription(**subscription_request.model_dump())
+
+    subscription =  Subscription(**subscription_request.model_dump()) if subscription_request else Subscription(type="default", target="default")
 
     if not manager.add_subscription(session_id, subscription):
         raise HTTPException(status_code=400, detail="Échec de l'ajout de l'abonnement")