refactor(git): share the info/exclude writer with the findings store

src/ClaudeDo.Worker/Skills/SessionSkillSeeder.cs

@@ -1,6 +1,5 @@
-using System.Diagnostics;
-using System.Text;
 using ClaudeDo.Data;
+using ClaudeDo.Worker.Git;
 using Microsoft.Extensions.Logging;
 
 namespace ClaudeDo.Worker.Skills;
@@ -35,7 +34,7 @@ public sealed class SessionSkillSeeder : ISessionSkillSeeder
             CopyDirectory(sourceDir, destDir);
 
             if (isWorktree)
-                await AppendExcludeLineAsync(workingDir, $"/.claude/skills/{name}/", ct);
+                await GitExcludeWriter.AppendLineAsync(workingDir, $"/.claude/skills/{name}/", ct);
         }
     }
 
@@ -53,64 +52,4 @@ public sealed class SessionSkillSeeder : ISessionSkillSeeder
         }
     }
 
-    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');
-    }
 }