feat(worker): resolve and seed session skills before each run

src/ClaudeDo.Worker/Skills/Interfaces/ISessionSkillSeeder.cs

@@ -0,0 +1,6 @@
+namespace ClaudeDo.Worker.Skills;
+
+public interface ISessionSkillSeeder
+{
+    Task SeedAsync(string workingDir, IReadOnlyList<string> skillNames, bool isWorktree, CancellationToken ct);
+}

src/ClaudeDo.Worker/Skills/SessionSkillSeeder.cs

@@ -0,0 +1,116 @@
+using System.Diagnostics;
+using System.Text;
+using ClaudeDo.Data;
+using Microsoft.Extensions.Logging;
+
+namespace ClaudeDo.Worker.Skills;
+
+public sealed class SessionSkillSeeder : ISessionSkillSeeder
+{
+    private readonly string _skillsRoot;
+    private readonly ILogger<SessionSkillSeeder> _logger;
+
+    public SessionSkillSeeder(ILogger<SessionSkillSeeder> logger, string? skillsRoot = null)
+    {
+        _logger = logger;
+        _skillsRoot = skillsRoot ?? Path.Combine(Paths.AppDataRoot(), "session-skills");
+    }
+
+    public async Task SeedAsync(string workingDir, IReadOnlyList<string> skillNames, bool isWorktree, CancellationToken ct)
+    {
+        if (skillNames.Count == 0) return;
+
+        var skillsDestRoot = Path.Combine(workingDir, ".claude", "skills");
+
+        foreach (var name in skillNames)
+        {
+            var sourceDir = Path.Combine(_skillsRoot, name);
+            if (!Directory.Exists(sourceDir))
+            {
+                _logger.LogWarning("Session skill '{SkillName}' not found on disk at {SourceDir}; skipping", name, sourceDir);
+                continue;
+            }
+
+            var destDir = Path.Combine(skillsDestRoot, name);
+            CopyDirectory(sourceDir, destDir);
+
+            if (isWorktree)
+                await AppendExcludeLineAsync(workingDir, $"/.claude/skills/{name}/", ct);
+        }
+    }
+
+    private static void CopyDirectory(string sourceDir, string destDir)
+    {
+        Directory.CreateDirectory(destDir);
+        foreach (var file in Directory.EnumerateFiles(sourceDir, "*", SearchOption.AllDirectories))
+        {
+            var relative = Path.GetRelativePath(sourceDir, file);
+            var destPath = Path.Combine(destDir, relative);
+            var destParent = Path.GetDirectoryName(destPath);
+            if (!string.IsNullOrEmpty(destParent))
+                Directory.CreateDirectory(destParent);
+            File.Copy(file, destPath, overwrite: true);
+        }
+    }
+
+    private static async Task AppendExcludeLineAsync(string workingDir, string excludeLine, CancellationToken ct)
+    {
+        var relativeExcludePath = await RunGitCaptureAsync(workingDir, ["rev-parse", "--git-path", "info/exclude"], ct);
+        var excludeFile = Path.IsPathRooted(relativeExcludePath)
+            ? relativeExcludePath
+            : Path.GetFullPath(Path.Combine(workingDir, relativeExcludePath));
+
+        var excludeDir = Path.GetDirectoryName(excludeFile);
+        if (!string.IsNullOrEmpty(excludeDir))
+            Directory.CreateDirectory(excludeDir);
+
+        if (File.Exists(excludeFile))
+        {
+            var existingLines = await File.ReadAllLinesAsync(excludeFile, ct);
+            if (existingLines.Any(l => l.Trim() == excludeLine))
+                return;
+        }
+
+        await File.AppendAllTextAsync(excludeFile, excludeLine + Environment.NewLine, ct);
+    }
+
+    private static async Task<string> RunGitCaptureAsync(string workingDir, IEnumerable<string> args, CancellationToken ct)
+    {
+        var psi = new ProcessStartInfo
+        {
+            FileName = "git",
+            RedirectStandardOutput = true,
+            RedirectStandardError = true,
+            UseShellExecute = false,
+            CreateNoWindow = true,
+            StandardOutputEncoding = Encoding.UTF8,
+            StandardErrorEncoding = Encoding.UTF8,
+        };
+        psi.ArgumentList.Add("-C");
+        psi.ArgumentList.Add(workingDir);
+        foreach (var a in args) psi.ArgumentList.Add(a);
+
+        using var proc = new Process { StartInfo = psi };
+        proc.Start();
+
+        await using var ctr = ct.Register(() =>
+        {
+            try { proc.Kill(entireProcessTree: true); }
+            catch { /* already exited */ }
+        });
+
+        var stdoutTask = proc.StandardOutput.ReadToEndAsync();
+        var stderrTask = proc.StandardError.ReadToEndAsync();
+
+        await proc.WaitForExitAsync(CancellationToken.None);
+        var stdout = await stdoutTask;
+        var stderr = await stderrTask;
+
+        ct.ThrowIfCancellationRequested();
+
+        if (proc.ExitCode != 0)
+            throw new InvalidOperationException($"git rev-parse --git-path failed (exit {proc.ExitCode}): {stderr.TrimEnd()}");
+
+        return stdout.TrimEnd('\r', '\n');
+    }
+}