- Add AssignmentJob model to track AI assignment progress
- Create startAIAssignmentJob mutation for background processing
- Add getAIAssignmentJobStatus query for polling progress
- Update AI assignment service with progress callback support
- Add progress bar UI showing batch/project processing status
- Add toast notifications for job completion/failure
- Add AI_SUGGESTIONS_READY notification type
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>