Update Resource Access

Update an existing resource access grant (change role).

This is a more atomic alternative to revoking and re-granting access. Preserves the access ID and created_at timestamp.

User must have write permission on the resource.

Note: For org-level permissions, use OrganizationMember roles instead.

:param request_fastapi: FastAPI request object. :param resource_type: Type of resource ("project"). :param resource_id: Resource ID. :param access_id: ResourceAccess ID to update. :param update_data: Update data containing new role_id. :param session: Database session. :return: Updated access entry.