An mcp grant lets its holder drive clients that reach admitted providers
with the credentials the deployment issued, not the caller's own, so the
role is declared per application and never spans them.
The unit test pins that boundary directly: a scoped grant reaches only
the named application, an unscoped one reaches nothing, and an ordinary
role still spans everything. The Keycloak realm builder, the LDAP entry
builder and the Open WebUI reconciler all resolve membership through the
one module this covers.
