nats nak w/ shared retry_backoff, exhausted log; no 'will retry' lie

crates/application/src/worker.rs

@@ -119,7 +119,7 @@ async fn dispatch(
                 }
                 Err(e) => {
                     // Running anyway could repeat a side effect; retry the delivery instead.
-                    tracing::warn!(handler = name, "ledger claim failed, will retry: {e}");
+                    tracing::warn!(handler = name, "ledger claim failed, nacking delivery: {e}");
                     any_transient = true;
                     continue;
                 }
@@ -146,7 +146,10 @@ async fn dispatch(
                     tracing::warn!(handler = name, "releasing ledger claim failed: {le}");
                 }
                 if e.is_transient() {
-                    tracing::warn!(handler = name, "transient handler error, will retry: {e}");
+                    tracing::warn!(
+                        handler = name,
+                        "transient handler error, nacking delivery (the backend logs if attempts are exhausted): {e}"
+                    );
                     any_transient = true;
                 } else {
                     tracing::warn!(