refactor(employees): simplify partial_update using ExternalSystemSyncMixin
Replaced _perform_user_update (180+ lines) with clean mixin approach:
Before:
- _perform_user_update(): 180 lines of manual LDAP/DB coordination
- Manual transaction management
- Direct DirectoryService.update_user() calls with transaction.atomic inside
- Complex error handling
- Duplicate email verification logic
After:
- partial_update(): delegates to super() + email verification (30 lines)
- perform_update(): only avatar handling (20 lines)
- prepare_external_data(): builds LDAP changes dict with avatar_bytes
- Миксин автоматически управляет транзакциями
Changes:
1. partial_update(): simplified to super() + email verification
2. perform_update(): handles avatar file -> ContentFile
3. prepare_external_data(): extracts LDAP fields (first_name, last_name, email, etc),
converts avatar to bytes, passes move_to_department_dn and group_cns
4. update_user_in_ldap_only(): updated signature to accept move_to_department_dn, group_cns
Code reduction: 200 lines -> 80 lines
Benefits: cleaner, automatic rollback, consistent with create()
Next: можно удалить _perform_user_update() если не используется
manage.py check: no issues