- Add milestone.freeze/start/close, task.close/reopen_closed/reopen_completed, propose.accept/reject/reopen to DEFAULT_PERMISSIONS
- Replace placeholder check_project_role with check_permission in proposes.py accept/reject/reopen
- Replace freeform permission strings with dotted names in milestone_actions.py
- Add task.close and task.reopen_* permission checks in tasks.py transition endpoint
- Admin role auto-inherits all new permissions via init_wizard