the ring reads out over ipc as turn decisions (V-564)

Same shape as TickTrace and RecentEvents: a bounded daemon ring, so the store
adapter refuses rather than pretending a table exists. No voice wiring means an
empty list and not an error, because a box with no voice path has had no turns
to arbitrate.

internal/ipc/coreapi.go

@@ -169,6 +169,13 @@ type SystemAPI interface {
 	// persisted — it's a daemon-level cache).
 	TickTrace(ctx context.Context) (TickTrace, error)
 
+	// TurnDecisions returns the newest turn arbitration records, newest first
+	// (V-564). Same shape as TickTrace and RecentEvents: a bounded in-memory
+	// ring on the daemon, so the store adapter returns an error rather than
+	// pretending a table exists. Empty is a normal answer — it means no turn
+	// has run since the daemon started.
+	TurnDecisions(ctx context.Context, n int) ([]TurnDecision, error)
+
 	// RecentEcosystemTraces reads the ecosystem call log, which lives in its
 	// own table so machine-rate traces never crowd out human-rate facts.
 	RecentEcosystemTraces(ctx context.Context, n int) ([]EcosystemTrace, error)