Constant RESTORE_REFERENT_MISSING_GATE 

pub const RESTORE_REFERENT_MISSING_GATE: StructuralGate;

A Restore whose repository referent does not exist (issue #393): the explicit spec.repository object, or the source.fromPolicy SnapshotPolicy the repository ref is derived from.

The readiness gate cannot verify a repository it cannot even look up, so the restore parks at phase: Pending and — critically — its policy.waitTimeout window is NOT opened (status.waitStartedAt stays unstamped) until the referent appears and its repository becomes Ready. Before #393 the gate fell through unverified here, so a slow-arriving referent silently spent the window; for a fromPolicy source, whose onMissingSnapshot defaults to Continue, a spent window means an EMPTY volume.

WARN, not Fail, for the reason POLICY_REPOSITORY_NOT_READY_GATE is: referents applied moments apart by GitOps are the ordinary case and resolve themselves within a requeue or two, so this must explain the park rather than independently turn a diagnostic red. What it must never be is INVISIBLE — a restore parked on a SnapshotPolicy that was never applied looks identical, by phase, to one that is simply still resolving.