feat: route publishes to jetstream with puback

src/NATS.Server/JetStream/Publish/JetStreamPublisher.cs

@@ -0,0 +1,30 @@
+namespace NATS.Server.JetStream.Publish;
+
+public sealed class JetStreamPublisher
+{
+    private readonly StreamManager _streamManager;
+
+    public JetStreamPublisher(StreamManager streamManager)
+    {
+        _streamManager = streamManager;
+    }
+
+    public bool TryCapture(string subject, ReadOnlyMemory<byte> payload, out PubAck ack)
+    {
+        var stream = _streamManager.FindBySubject(subject);
+        if (stream == null)
+        {
+            ack = new PubAck();
+            return false;
+        }
+
+        var seq = stream.Store.AppendAsync(subject, payload, default).GetAwaiter().GetResult();
+        ack = new PubAck
+        {
+            Stream = stream.Config.Name,
+            Seq = seq,
+        };
+
+        return true;
+    }
+}