Implement PurgeScalingGroup Action

[jopemachine]

Objective

Implement DeleteScalingGroup action as the simplest operation to validate the entire pattern.

Implementation Details

• actions/delete_scaling_group.py: Delete action definition (~35 lines)
• service.py: Add delete_scaling_group method (~15 lines)
• processors.py: Add delete processor (~10 lines)
• repository.py: Add delete method (~25 lines)
• db_source/db_source.py: Add delete method (~30 lines)
• GraphQL mutation modification (legacy → new pattern) (~20 lines)
• Unit tests:
  • test_delete_scaling_group_service.py (~60 lines)
  • test_delete_scaling_group_repository.py (~60 lines)

Estimated Lines

~255 lines

Dependencies

• Story 1: Foundation Structure Setup

Acceptance Criteria

• [ ] DeleteScalingGroupAction and result classes implemented
• [ ] Service method delegates to repository
• [ ] Repository applies resilience policies
• [ ] DBSource handles database deletion
• [ ] GraphQL mutation uses processors.scaling_group.delete.wait_for_complete()
• [ ] Unit tests pass with mocked dependencies

JIRA Issue: BA-3483