Add comprehensive session debugging

- Fix SessionMiddleware parameters (remove unsupported options)
- Add session debugging in auth callback after saving
- Fix cookie name check to use default 'session'
- Compare session state between save and read operations
- This will show exactly where session data is lost

backend/app.py

@@ -70,9 +70,7 @@ if is_huggingface_space():
         max_age=3600,  # Shorter expiry for HF Spaces (1 hour)
         same_site="none",  # More permissive for HF Spaces proxy
         https_only=True,  # HF Spaces uses HTTPS
-        session_cookie="hf_session",  # Custom cookie name for HF Spaces
-        path="/",  # Explicit path
-        domain=None,  # Let HF Spaces handle domain
+        # Note: SessionMiddleware doesn't support custom cookie name, using default
     )
 else:
     # Local development session configuration

backend/dependencies.py

@@ -128,7 +128,7 @@ def get_current_user_optional(request: Request) -> Optional[Dict[str, Any]]:
                 # Log HF-specific session debugging info
                 cookies = request.cookies
                 logger.warning(f"🍪 HF Spaces cookies: {list(cookies.keys())}")
-                logger.warning(f"🍪 Session cookie present: {'hf_session' in cookies}")
+                logger.warning(f"🍪 Session cookie present: {'session' in cookies}")  # Default SessionMiddleware cookie name
                 
                 # Check if session middleware is properly initialized
                 session_data = dict(request.session) if hasattr(request.session, 'keys') else {}

backend/routers/auth.py

@@ -210,6 +210,13 @@ async def oauth_callback(request: Request, code: str, state: str):
             logger.info(f"✅ Session verification successful: {stored_user['username']}")
         else:
             logger.error("❌ Session verification failed - user not found after saving")
+        
+        # Debug session state after saving
+        from utils.environment import is_huggingface_space
+        if is_huggingface_space():
+            session_keys = list(request.session.keys()) if hasattr(request.session, 'keys') else []
+            logger.info(f"🔍 Auth callback - session keys after save: {session_keys}")
+            logger.info(f"🔍 Auth callback - full session: {dict(request.session)}")
             
     except Exception as e:
         logger.error(f"❌ Failed to save user to session: {e}")