feat: remove spectre.console

Replace `Spectre.Console.Cli` with `System.CommandLine`

src/process.dummy.app/_commands/EchoCommand.cs

@@ -1,23 +1,29 @@
 // Copyright (c) The Geekeey Authors
 // SPDX-License-Identifier: EUPL-1.2
 
-using Spectre.Console.Cli;
+using System.CommandLine;
 
-internal sealed class EchoCommand : AsyncOutputCommand<EchoCommand.Settings>
+internal sealed class EchoCommand : Command
 {
-	public sealed class Settings : OutputCommandSettings
+	private static readonly Option<OutputTarget> Target = new("--target") { DefaultValueFactory = _ => OutputTarget.StdOut };
+	private static readonly Option<string> Separator = new("--separator") { DefaultValueFactory = _ => " " };
+	private static readonly Argument<string[]> Items = new("line") { Arity = ArgumentArity.ZeroOrMore, DefaultValueFactory = _ => [] };
+
+	public EchoCommand() : base("echo")
 	{
-		[CommandOption("--separator <char>")] public string Separator { get; init; } = " ";
-		[CommandArgument(0, "[line]")] public string[] Items { get; init; } = [];
+		Add(Target);
+		Add(Separator);
+		Add(Items);
+		SetAction(ExecuteAsync);
 	}
 
-	public override async Task<int> ExecuteAsync(CommandContext context, Settings settings, CancellationToken cancellationToken)
+	public async Task<int> ExecuteAsync(ParseResult result, CancellationToken cancellationToken)
 	{
 		using var output = Output.Connect();
 
-		foreach (var writer in output.GetWriters(settings.Target))
+		foreach (var writer in output.GetWriters(result.GetValue(Target)))
 		{
-			await writer.WriteLineAsync(string.Join(settings.Separator, settings.Items));
+			await writer.WriteLineAsync(string.Join(result.GetRequiredValue(Separator), result.GetRequiredValue(Items)));
 		}
 
 		return 0;