feat(nats): migrate to JetStream — at-least-once delivery with durable consumer

crates/bootstrap/src/factory.rs

@@ -44,6 +44,9 @@ pub async fn build(cfg: &Config) -> Infrastructure {
         Some(url) => match async_nats::connect(url).await {
             Ok(client) => {
                 tracing::info!("Connected to NATS at {url}");
+                if let Err(e) = nats::ensure_stream(&client).await {
+                    tracing::warn!("JetStream stream setup failed: {e} — events may be lost");
+                }
                 Arc::new(EventPublisherAdapter::new(NatsTransport::new(client)))
             }
             Err(e) => {