fix: broadcast AP Update after poster sync to fix missing posters on remote instances

New movies had no poster at AP broadcast time (race between poster sync
and ReviewLogged handler). PosterSynced event now fires after sync
completes, triggering Update notes so remote apps get the poster URL.

crates/adapters/nats/src/subject.rs

@@ -19,6 +19,7 @@ pub fn event_to_subject(prefix: &str, event: &DomainEvent) -> String {
         DomainEvent::WrapUpRequested { .. } => "wrapup.requested",
         DomainEvent::WrapUpCompleted { .. } => "wrapup.completed",
         DomainEvent::SearchReindexRequested => "search.reindex.requested",
+        DomainEvent::PosterSynced { .. } => "poster.synced",
     };
     format!("{prefix}.{suffix}")
 }