fix: defer blocked deliveries, claim owner token

crates/domain/src/events.rs

@@ -148,6 +148,11 @@ pub enum DomainEvent {
 pub trait AckHandle: Send + Sync {
     async fn ack(&self) -> Result<(), DomainError>;
     async fn nack(&self) -> Result<(), DomainError>;
+    /// Redeliver after `delay` without counting a failed attempt: for a
+    /// delivery that was not tried (it is blocked behind a live claim), so it
+    /// must not burn the retry budget that `nack` spends. A broker may still
+    /// count the redelivery itself: JetStream does, toward `max_deliver`.
+    async fn defer(&self, delay: std::time::Duration) -> Result<(), DomainError>;
 }
 
 /// Stable identity of one queued event; the key for de-duplicating deliveries.
@@ -194,6 +199,10 @@ impl EventEnvelope {
         self.ack.ack().await
     }
 
+    pub async fn defer(self, delay: std::time::Duration) -> Result<(), DomainError> {
+        self.ack.defer(delay).await
+    }
+
     pub async fn nack(self) -> Result<(), DomainError> {
         self.ack.nack().await
     }