`omnigraph schema apply` against a cluster-managed graph's storage root bypassed
the cluster ledger/recovery/approvals. Mirror `init`'s refusal: on the embedded
(direct-store) path, if the resolved URI is inside a cluster
(`cluster_root_for_graph_uri`), bail and point at `cluster apply`. The served
(`--server`) path is unaffected — it addresses a server, not a storage root.
`schema plan`/`show` (read-only) are untouched.
Two e2e tests injected "out-of-band drift" via this exact CLI path; since the
CLI now refuses it, they inject drift via a direct engine `apply_schema` against
the storage root instead — a faithful control-plane bypass, which is what
out-of-band drift is. New regression:
`schema_apply_refuses_a_cluster_managed_graph_and_signposts_cluster_apply`.
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>