chore: add .worktrees/ to .gitignore for isolated development

.gitignore

@@ -161,6 +161,9 @@ FodyWeavers.xsd
 ## Go reference implementation
 golang/
 
+## Git worktrees
+.worktrees/
+
 ## OS
 .DS_Store
 Thumbs.db

src/NATS.Server/NatsClient.cs

@@ -356,14 +356,14 @@ public sealed class NatsClient : IDisposable
                     continue;
                 }
 
-                var currentPingsOut = Interlocked.Increment(ref _pingsOut);
-                if (currentPingsOut > _options.MaxPingsOut)
+                if (Volatile.Read(ref _pingsOut) + 1 > _options.MaxPingsOut)
                 {
                     _logger.LogDebug("Client {ClientId} stale connection — closing", Id);
                     await SendErrAndCloseAsync(NatsProtocol.ErrStaleConnection);
                     return;
                 }
 
+                var currentPingsOut = Interlocked.Increment(ref _pingsOut);
                 _logger.LogDebug("Client {ClientId} sending PING ({PingsOut}/{MaxPingsOut})",
                     Id, currentPingsOut, _options.MaxPingsOut);
                 try