feat(cli): add sm skill commands for managing Claude skills

cli/SimpleModule.Cli/Commands/Skill/SkillAddCommand.cs

@@ -0,0 +1,101 @@
+using SimpleModule.Cli.Infrastructure;
+using Spectre.Console;
+using Spectre.Console.Cli;
+
+namespace SimpleModule.Cli.Commands.Skill;
+
+public sealed class SkillAddCommand : AsyncCommand<SkillAddSettings>
+{
+    public override async Task<int> ExecuteAsync(CommandContext context, SkillAddSettings settings)
+    {
+        var solution = SolutionContext.Discover();
+        if (solution is null)
+        {
+            AnsiConsole.MarkupLine(
+                "[red]No .slnx file found. Run this command from inside a SimpleModule project.[/]"
+            );
+            return 1;
+        }
+
+        var name = settings.ResolveName();
+        var skillDir = SkillWriter.GetSkillDirectory(solution.RootPath, name);
+
+        if (Directory.Exists(skillDir) && !settings.Force && !settings.DryRun)
+        {
+            AnsiConsole.MarkupLine(
+                $"[red]Skill '{Markup.Escape(name)}' already exists at {Markup.Escape(Path.GetRelativePath(solution.RootPath, skillDir))}. Use --force to overwrite or 'sm skill update' to refresh.[/]"
+            );
+            return 1;
+        }
+
+        SkillSource source;
+        FetchedSkill fetched;
+
+        if (string.IsNullOrWhiteSpace(settings.Source))
+        {
+            source = new SkillSource(SkillSourceType.Scaffold, "scaffold");
+            fetched = SkillWriter.BuildScaffold(name, settings.Description);
+            AnsiConsole.MarkupLine($"[blue]Scaffolding new skill '{Markup.Escape(name)}'.[/]");
+        }
+        else
+        {
+            source = SkillSource.Parse(settings.Source!);
+            AnsiConsole.MarkupLine(
+                $"[blue]Fetching skill '{Markup.Escape(name)}' from {Markup.Escape(source.Type.ToString().ToLowerInvariant())} source '{Markup.Escape(source.CanonicalSource)}'...[/]"
+            );
+
+            try
+            {
+                fetched = await new SkillFetcher().FetchAsync(source).ConfigureAwait(false);
+            }
+            catch (InvalidOperationException ex)
+            {
+                AnsiConsole.MarkupLine(
+                    $"[red]Failed to fetch skill: {Markup.Escape(ex.Message)}[/]"
+                );
+                return 1;
+            }
+        }
+
+        if (settings.DryRun)
+        {
+            AnsiConsole.MarkupLine("[yellow]Dry run — no files will be written.[/]");
+            foreach (var file in fetched.Files)
+            {
+                var rel = Path.GetRelativePath(
+                    solution.RootPath,
+                    Path.Combine(skillDir, file.RelativePath)
+                );
+                AnsiConsole.MarkupLine($"  [green]CREATE[/] {Markup.Escape(rel)}");
+            }
+
+            AnsiConsole.MarkupLine(
+                $"  [green]UPDATE[/] {Markup.Escape(SkillsLockFile.FileName)} (entry '{Markup.Escape(name)}')"
+            );
+            return 0;
+        }
+
+        var written = SkillWriter.WriteFiles(skillDir, fetched.Files, replace: settings.Force);
+        foreach (var path in written)
+        {
+            var rel = Path.GetRelativePath(solution.RootPath, Path.Combine(skillDir, path));
+            AnsiConsole.MarkupLine($"  [green]CREATE[/] {Markup.Escape(rel)}");
+        }
+
+        var lockFile = SkillsLockFile.Load(solution.RootPath);
+        lockFile.Skills[name] = new SkillsLockEntry
+        {
+            Source = source.CanonicalSource,
+            SourceType = source.SourceTypeId,
+            Ref = source.Ref,
+            ComputedHash = fetched.ComputedHash,
+        };
+        lockFile.Save(solution.RootPath);
+
+        AnsiConsole.MarkupLine($"  [green]UPDATE[/] {Markup.Escape(SkillsLockFile.FileName)}");
+        AnsiConsole.MarkupLine(
+            $"\n[green]Skill '{Markup.Escape(name)}' added.[/] [dim]({fetched.Files.Count} file(s), hash {fetched.ComputedHash[..8]})[/]"
+        );
+        return 0;
+    }
+}

cli/SimpleModule.Cli/Commands/Skill/SkillAddSettings.cs

@@ -0,0 +1,46 @@
+using System.ComponentModel;
+using Spectre.Console;
+using Spectre.Console.Cli;
+
+namespace SimpleModule.Cli.Commands.Skill;
+
+public sealed class SkillAddSettings : CommandSettings
+{
+    [CommandArgument(0, "[name]")]
+    [Description("Skill name in kebab-case (e.g. shadcn, react-expert)")]
+    public string? Name { get; set; }
+
+    [CommandOption("--source <SOURCE>")]
+    [Description(
+        "Source for the skill. GitHub: 'owner/repo' optionally followed by '/path' and '@ref'. Local: a directory path. Omit to scaffold a new template."
+    )]
+    public string? Source { get; set; }
+
+    [CommandOption("--description <TEXT>")]
+    [Description("Description used when scaffolding a new skill (only when --source is omitted).")]
+    public string? Description { get; set; }
+
+    [CommandOption("--force")]
+    [Description("Overwrite the skill directory if it already exists.")]
+    public bool Force { get; set; }
+
+    [CommandOption("--dry-run")]
+    [Description("Show what would be written without modifying any files.")]
+    public bool DryRun { get; set; }
+
+    public string ResolveName()
+    {
+        if (string.IsNullOrWhiteSpace(Name))
+        {
+            Name = AnsiConsole.Ask<string>("Skill name (kebab-case):");
+        }
+
+        Name = SkillNameValidator.Normalize(Name);
+        if (!SkillNameValidator.IsValid(Name))
+        {
+            throw new InvalidOperationException(SkillNameValidator.ValidationMessage(Name));
+        }
+
+        return Name;
+    }
+}