feat: remove spectre.console

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

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

@@ -2,21 +2,26 @@
 // SPDX-License-Identifier: EUPL-1.2
 
 using System.Buffers;
+using System.CommandLine;
 using System.Globalization;
 
-using Spectre.Console.Cli;
-
-internal sealed class LengthCommand : AsyncOutputCommand<LengthCommand.Settings>
+internal sealed class LengthCommand : Command
 {
-	public sealed class Settings : OutputCommandSettings
+	private static readonly Option<OutputTarget> Target = new("--target") { DefaultValueFactory = _ => OutputTarget.StdOut };
+	private static readonly Option<int> Buffer = new("--buffer") { DefaultValueFactory = _ => 81920 };
+
+	public LengthCommand() : base("length")
 	{
+		Add(Target);
+		Add(Buffer);
+		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();
 
-		using var buffer = MemoryPool<byte>.Shared.Rent(81920);
+		using var buffer = MemoryPool<byte>.Shared.Rent(result.GetRequiredValue(Buffer));
 
 		var count = 0L;
 		while (true)
@@ -30,7 +35,7 @@ internal sealed class LengthCommand : AsyncOutputCommand<LengthCommand.Settings>
 			count += bytesRead;
 		}
 
-		foreach (var writer in output.GetWriters(settings.Target))
+		foreach (var writer in output.GetWriters(result.GetRequiredValue(Target)))
 		{
 			await writer.WriteLineAsync(count.ToString(CultureInfo.InvariantCulture));
 		}