feat: add route propagation and bootstrap js gateway leaf services

src/NATS.Server/LeafNodes/LeafConnection.cs

@@ -0,0 +1,11 @@
+namespace NATS.Server.LeafNodes;
+
+public sealed class LeafConnection
+{
+    public string RemoteEndpoint { get; }
+
+    public LeafConnection(string remoteEndpoint)
+    {
+        RemoteEndpoint = remoteEndpoint;
+    }
+}

src/NATS.Server/LeafNodes/LeafNodeManager.cs

@@ -0,0 +1,31 @@
+using Microsoft.Extensions.Logging;
+using NATS.Server.Configuration;
+
+namespace NATS.Server.LeafNodes;
+
+public sealed class LeafNodeManager : IAsyncDisposable
+{
+    private readonly LeafNodeOptions _options;
+    private readonly ServerStats _stats;
+    private readonly ILogger<LeafNodeManager> _logger;
+
+    public LeafNodeManager(LeafNodeOptions options, ServerStats stats, ILogger<LeafNodeManager> logger)
+    {
+        _options = options;
+        _stats = stats;
+        _logger = logger;
+    }
+
+    public Task StartAsync(CancellationToken ct)
+    {
+        _logger.LogDebug("Leaf manager started (listen={Host}:{Port})", _options.Host, _options.Port);
+        Interlocked.Exchange(ref _stats.Leafs, 0);
+        return Task.CompletedTask;
+    }
+
+    public ValueTask DisposeAsync()
+    {
+        _logger.LogDebug("Leaf manager stopped");
+        return ValueTask.CompletedTask;
+    }
+}