fix: defer blocked deliveries, claim owner token

crates/adapters/nats/src/consumer.rs

@@ -48,6 +48,16 @@ impl AckHandle for NatsJetStreamAckHandle {
             .await
             .map_err(|e| DomainError::InfrastructureError(e.to_string()))
     }
+
+    /// JetStream counts every redelivery toward `max_deliver`, deferrals
+    /// included. The delay is at least the remaining claim lease, so the
+    /// deliveries allowed by `max_deliver` still span more than one lease.
+    async fn defer(&self, delay: std::time::Duration) -> Result<(), DomainError> {
+        self.message
+            .ack_with(AckKind::Nak(Some(delay)))
+            .await
+            .map_err(|e| DomainError::InfrastructureError(e.to_string()))
+    }
 }
 
 // ── Core NATS ack handle (no-op) ─────────────────────────────────────────────
@@ -62,6 +72,9 @@ impl AckHandle for NoopAck {
     async fn nack(&self) -> Result<(), DomainError> {
         Ok(())
     }
+    async fn defer(&self, _: std::time::Duration) -> Result<(), DomainError> {
+        Ok(())
+    }
 }
 
 // ── Envelope construction helpers ────────────────────────────────────────────