4e9b31377b
- Make residence_id nullable in contractor model - Add created_by_id field to track contractor creator - Update access control: personal contractors visible only to creator, residence contractors visible to all residence users - Add database migration for schema changes - Update admin panel DTOs and handlers for optional residence - Fix test utilities for new model structure 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>