Add Security Manager model methods

Summary

Add model-layer support for Security Manager role assignment. Methods will be gated behind an environment variable to ensure safe deployment.

Implementation Details

  • Add add_security_manager method to Group model
  • Add add_security_manager method to ProjectTeam model
  • Add security_managers scope to Member model
  • Delegate add_security_manager in Project model
  • All methods should check the environment variable before executing

Acceptance Criteria

  • group.add_security_manager(user) works when env var is enabled
  • project.add_security_manager(user) works when env var is enabled
  • Member.security_managers scope returns correct results when enabled
  • Methods are no-ops when the environment variable is disabled
  • Existing member assignment methods remain unchanged

Environment Variable

GITLAB_SECURITY_MANAGER_ROLE=true to enable

Depends on: Issue #582639

Edited by Miki Amos