Add cleanup for incomplete matches from past days

- Add _cleanup_old_incomplete_matches() to close matches 2+ days old as 'failed'
- Add _get_yesterday_incomplete_matches() to find yesterday's incomplete matches
- Add _get_or_create_today_fixture() to ensure new matches go to today's fixture
- Add yesterday_fixture_id attribute to track yesterday's fixture for completion
- Modify initialize() to process past incomplete matches before starting
- Pre-create today's fixture when yesterday's incomplete matches are found
- Ensure new matches are created in today's fixture, not yesterday's