add socketio to global state

backend/src/state.py

@@ -2,6 +2,7 @@ from dataclasses import dataclass, field
 from sqlite3 import Cursor
 
 from flask import Flask
+from flask_socketio import SocketIO
 
 from .room import Room
 
@@ -9,5 +10,6 @@ from .room import Room
 @dataclass
 class State:
     app: Flask
+    socketio: SocketIO
     db: Cursor
     rooms: dict[int, Room] = field(default_factory=dict)  # { room_id: room, ... }