fix(cli): handle 404 in versions command instead of crashing

src/Netclaw.SkillServer.Cli/Commands/VersionsCommand.cs

@@ -4,6 +4,7 @@
 // </copyright>
 // -----------------------------------------------------------------------
 
+using System.Net;
 using System.Text.Json;
 using Netclaw.SkillClient;
 using Netclaw.SkillServer.Cli.Json;
@@ -22,7 +23,21 @@ public static async Task<int> ExecuteAsync(ParsedArgs args, SkillServerClient cl
         }
 
         var name = args.Positional[0];
-        var versions = await client.GetSkillVersionsAsync(name);
+
+        IReadOnlyList<SkillVersionSummary> versions;
+        try
+        {
+            versions = await client.GetSkillVersionsAsync(name);
+        }
+        catch (HttpRequestException ex) when (ex.StatusCode == HttpStatusCode.NotFound)
+        {
+            ConsoleOutput.WriteError($"Skill '{name}' not found.");
+            return 1;
+        }
+        catch (HttpRequestException ex)
+        {
+            return ConsoleOutput.HandleHttpError(ex);
+        }
 
         if (args.OutputFormat == "json")
         {

tests/Netclaw.SkillServer.Cli.Tests/VersionsCommandTests.cs

@@ -0,0 +1,93 @@
+// -----------------------------------------------------------------------
+// <copyright file="VersionsCommandTests.cs" company="Petabridge, LLC">
+//      Copyright (C) 2026 - 2026 Petabridge, LLC <https://petabridge.com>
+// </copyright>
+// -----------------------------------------------------------------------
+
+using System.Net;
+using System.Text;
+using System.Text.Json;
+using Netclaw.SkillClient;
+using Netclaw.SkillServer.Cli.Commands;
+using Xunit;
+
+namespace Netclaw.SkillServer.Cli.Tests;
+
+public sealed class VersionsCommandTests
+{
+    [Fact]
+    public async Task ExecuteAsync_MissingSkill_ReturnsOneWithoutThrowing()
+    {
+        // Server returns 404 for a skill that isn't published (regression test for #142).
+        var handler = new QueuedHandler(new HttpResponseMessage(HttpStatusCode.NotFound));
+        using var client = CreateClient(handler);
+
+        var exitCode = await VersionsCommand.ExecuteAsync(
+            new ParsedArgs { Positional = ["no-such-skill"] },
+            client);
+
+        Assert.Equal(1, exitCode);
+        Assert.Single(handler.Requests);
+    }
+
+    [Fact]
+    public async Task ExecuteAsync_ExistingSkill_ReturnsZeroAndListsVersions()
+    {
+        var versions = new[]
+        {
+            new SkillVersionSummary
+            {
+                Name = "example-skill",
+                Version = "1.0.0",
+                Sha256 = "abc123",
+                PublishedAt = DateTimeOffset.UtcNow,
+                IsLatest = true
+            }
+        };
+        var json = JsonSerializer.Serialize(
+            (IReadOnlyList<SkillVersionSummary>)versions,
+            SkillServerClientJsonContext.Default.IReadOnlyListSkillVersionSummary);
+        var handler = new QueuedHandler(new HttpResponseMessage(HttpStatusCode.OK)
+        {
+            Content = new StringContent(json, Encoding.UTF8, "application/json")
+        });
+        using var client = CreateClient(handler);
+
+        var exitCode = await VersionsCommand.ExecuteAsync(
+            new ParsedArgs { Positional = ["example-skill"] },
+            client);
+
+        Assert.Equal(0, exitCode);
+    }
+
+    private static SkillServerClient CreateClient(HttpMessageHandler handler)
+    {
+        return new SkillServerClient(new HttpClient(handler)
+        {
+            BaseAddress = new Uri("https://example.test/")
+        });
+    }
+
+    private sealed class QueuedHandler : HttpMessageHandler
+    {
+        private readonly Queue<HttpResponseMessage> _responses;
+
+        public QueuedHandler(params HttpResponseMessage[] responses)
+        {
+            _responses = new Queue<HttpResponseMessage>(responses);
+        }
+
+        public List<string> Requests { get; } = [];
+
+        protected override Task<HttpResponseMessage> SendAsync(
+            HttpRequestMessage request,
+            CancellationToken cancellationToken)
+        {
+            Requests.Add(request.RequestUri?.AbsolutePath ?? "");
+
+            return Task.FromResult(_responses.Count == 0
+                ? new HttpResponseMessage(HttpStatusCode.OK)
+                : _responses.Dequeue());
+        }
+    }
+}