Add Create-Role-from-Preset GraphQL mutation + adapter

Add a Strawberry GraphQL mutation and adapter wiring to instantiate a role from a preset. Input: role_preset_id, scope_type, scope_id. The adapter maps the input to the action and invokes the processor, using the shared v2 DTOs.

JIRA Issue: BA-6321

Start by locating the existing Strawberry GraphQL mutations, adapter wiring, action, processor, and shared v2 DTOs for role operations. Implement the role-preset mutation with role_preset_id, scope_type, and scope_id, then verify that the adapter maps the input and invokes the processor using the shared DTOs.

Written by the indexing model from the issue text.