feat: centralize NATS message broker implementation in infra and abstract its usage in API and worker

notes-domain/Cargo.toml

@@ -12,6 +12,7 @@ serde_json = "1.0.146"
 thiserror = "2.0.17"
 tracing = "0.1"
 uuid = { version = "1.19.0", features = ["v4", "serde"] }
+futures-core = "0.3"
 
 [dev-dependencies]
 tokio = { version = "1", features = ["rt", "macros"] }

notes-domain/src/ports.rs

@@ -42,4 +42,10 @@ pub trait LinkRepository: Send + Sync {
 pub trait MessageBroker: Send + Sync {
     /// Publish an event when a note is created or updated.
     async fn publish_note_updated(&self, note: &Note) -> DomainResult<()>;
+
+    /// Subscribe to note update events.
+    /// Returns a stream of notes that have been updated.
+    async fn subscribe_note_updates(
+        &self,
+    ) -> DomainResult<std::pin::Pin<Box<dyn futures_core::Stream<Item = Note> + Send>>>;
 }