- Replace synchronous await classifier.classify_document() with extract_and_classify.delay()
- Set doc.status='processing' and commit before dispatching Celery task
- Return {'document_id': str, 'status': 'processing'} instead of assigned topics
- Promote test_reclassify_requeues_celery from xfail stub to passing test
- Add test_reclassify_cross_user_returns_404 for IDOR security invariant (T-07-10)