Implement Create-Role-from-Preset action + repository

Implement the service action and repository creator that instantiates a role from a role preset. Flow: look up the preset by id, read its role_permission_preset entries, and create a new role plus role_permission rows as a shallow snapshot bound to the target scope (scope_type/scope_id). Copy preset.auto_assign onto the generated role. Reuse the existing role creator / object-permission creation path as a single race-free operation. The instantiated role has no further relationship with the preset.

JIRA Issue: BA-6320