Add debugging and validation for cluster topologies

lib/aprsme/cluster/topology.ex

@@ -2,12 +2,28 @@ defmodule Aprsme.Cluster.Topology do
   @moduledoc """
   Wrapper for Cluster.Supervisor that only starts when clustering is enabled.
   """
+  require Logger
 
   def child_spec(opts) do
     if Application.get_env(:aprsme, :cluster_enabled, false) do
       topologies = Application.get_env(:libcluster, :topologies, [])
-      supervisor_opts = Keyword.merge([name: Aprsme.ClusterSupervisor], opts)
-      {Cluster.Supervisor, [topologies, supervisor_opts]}
+      
+      # Log the configuration for debugging
+      Logger.info("Cluster.Topology starting with topologies: #{inspect(topologies)}")
+      
+      # Ensure we have valid topologies
+      if topologies == [] or topologies == nil do
+        Logger.warning("No libcluster topologies configured, clustering will not work")
+        # Return a no-op spec
+        %{
+          id: __MODULE__,
+          start: {__MODULE__, :start_link, [opts]},
+          type: :worker
+        }
+      else
+        supervisor_opts = Keyword.merge([name: Aprsme.ClusterSupervisor], opts)
+        {Cluster.Supervisor, [topologies, supervisor_opts]}
+      end
     else
       # Return a no-op spec when clustering is disabled
       %{