Fix lint issues in pet detection integration

- Import PetsConfig directly instead of forward ref string
- Fix import sorting in worker.py, queries.py, constants.py
- Remove unused imports in profiles.py, trainer.py, processor.py

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

vigilar/detection/trainer.py

@@ -2,7 +2,7 @@
 
 import logging
 import shutil
-from dataclasses import dataclass, field
+from dataclasses import dataclass
 from pathlib import Path
 
 log = logging.getLogger(__name__)