fix: enhance todo list rendering with robust error handling and validation

- Add comprehensive validation in getLatestTodo function to ensure parsed JSON contains valid todo arrays
- Implement normalizedTodos logic in TodoListDisplay component to filter out invalid todo items
- Add fallback handling for edge cases where todo data might be malformed or missing
- Ensure todo items have required properties (id, content, status) before rendering
- Fixes issue #5916 where todo lists would not render properly

Author: roomote