feat: implement state expiry for chores and rewards, adding scheduler and event handling

backend/main.py

@@ -27,6 +27,7 @@ from events.sse import sse_response_for_user, send_to_user
 from api.utils import get_current_user_id
 from utils.account_deletion_scheduler import start_deletion_scheduler
 from utils.digest_scheduler import start_digest_scheduler
+from utils.state_expiry_scheduler import start_state_expiry_scheduler
 
 # Configure logging once at application startup
 logging.basicConfig(
@@ -140,6 +141,7 @@ createDefaultRewards()
 start_background_threads()
 start_deletion_scheduler()
 start_digest_scheduler(app)
+start_state_expiry_scheduler(app)
 
 if __name__ == '__main__':
     app.run(debug=False, host='0.0.0.0', port=5000, threaded=True)