feat: enforce jetstream retention and limits

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

@@ -11,19 +11,14 @@ public sealed class JetStreamPublisher
 
     public bool TryCapture(string subject, ReadOnlyMemory<byte> payload, out PubAck ack)
     {
-        var stream = _streamManager.FindBySubject(subject);
-        if (stream == null)
+        var captured = _streamManager.Capture(subject, payload);
+        if (captured == 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,
-        };
+        ack = captured;
 
         return true;
     }