Fix issues

Author: daxian-dbw

shell/AIShell.Kernel/Command/CommandRunner.cs

@@ -58,15 +58,12 @@ internal void LoadCommands(IEnumerable<CommandBase> commands, string agentName)
             command.Shell = _shell;
             command.Source = agentName;
 
+            // The 'command.Name' is included in the 'command.Aliases' collection.
             // TODO: need to think about how to handle command names/aliases collision.
             // We don't handle collision today -- it will throw when collision happens.
-            _commands.Add(command.Name, command);
             foreach (string alias in command.Aliases)
             {
-                if (!string.IsNullOrWhiteSpace(alias))
-                {
-                    _commands.Add(alias, command);
-                }
+                _commands.Add(alias, command);
             }
         }
     }
@@ -89,14 +86,11 @@ internal void UnloadAgentCommands()
 
         foreach (var command in agentCommands)
         {
+            // The 'command.Name' is included in the 'command.Aliases' collection.
             // TODO: need to update accordingly when we handle command names/aliases collision.
-            _commands.Remove(command.Name);
             foreach (string alias in command.Aliases)
             {
-                if (!string.IsNullOrWhiteSpace(alias))
-                {
-                    _commands.Remove(alias);
-                }
+                _commands.Remove(alias);
             }
 
             command.Dispose();

shell/AIShell.Kernel/Command/HelpCommand.cs

@@ -17,7 +17,7 @@ private void HelpAction()
         var host = shellImpl.Host;
 
         var commands = shellImpl.CommandRunner.Commands;
-        var list = commands.Values.Order(new CommandComparer()).ToList();
+        var list = commands.Values.Distinct().Order(new CommandComparer()).ToList();
 
         host.WriteLine();
         host.MarkupLine("[bold white]-[/] Type then press [bold olive underline]Enter[/] to chat with the chosen AI agent.");