Merge claudedo/ebd5a205ecfe40c298e3995f9f92f0a1

src/ClaudeDo.Installer/Core/AutostartShortcut.cs

@@ -11,13 +11,26 @@ public static class AutostartShortcut
 
     public static string PathIn(string startupDir) => Path.Combine(startupDir, FileName);
 
-    public static void Install(string startupDir, string workerExe)
+    /// <summary>Creates or updates the Startup shortcut. Returns false if it already pointed at <paramref name="workerExe"/> and was left untouched.</summary>
+    public static bool Install(string startupDir, string workerExe)
     {
         Directory.CreateDirectory(startupDir);
+        var shortcutPath = PathIn(startupDir);
+        if (File.Exists(shortcutPath))
+        {
+            var existingTarget = ShortcutFactory.TryGetTarget(shortcutPath);
+            if (existingTarget is not null && PathsEqual(existingTarget, workerExe))
+                return false;
+        }
+
         var workingDir = Path.GetDirectoryName(workerExe) ?? startupDir;
-        ShortcutFactory.CreateShortcut(PathIn(startupDir), workerExe, workingDir, "ClaudeDo background worker");
+        ShortcutFactory.CreateShortcut(shortcutPath, workerExe, workingDir, "ClaudeDo background worker");
+        return true;
     }
 
+    private static bool PathsEqual(string a, string b) =>
+        string.Equals(Path.GetFullPath(a), Path.GetFullPath(b), StringComparison.OrdinalIgnoreCase);
+
     public static void Remove(string startupDir)
     {
         var path = PathIn(startupDir);

src/ClaudeDo.Installer/Core/ShortcutFactory.cs

@@ -6,6 +6,8 @@ namespace ClaudeDo.Installer.Core;
 
 public static class ShortcutFactory
 {
+    private const int SlgpRawPath = 0x4;
+
     public static void CreateShortcut(string shortcutPath, string targetPath, string workingDir, string description)
     {
         var link = (IShellLink)new ShellLink();
@@ -18,6 +20,24 @@ public static class ShortcutFactory
         file.Save(shortcutPath, false);
     }
 
+    /// <summary>Reads the target path of an existing .lnk, or null if it can't be read (missing/corrupt).</summary>
+    public static string? TryGetTarget(string shortcutPath)
+    {
+        try
+        {
+            var link = (IShellLink)new ShellLink();
+            ((IPersistFile)link).Load(shortcutPath, 0);
+            var sb = new StringBuilder(260);
+            link.GetPath(sb, sb.Capacity, IntPtr.Zero, SlgpRawPath);
+            var path = sb.ToString();
+            return path.Length == 0 ? null : path;
+        }
+        catch (Exception)
+        {
+            return null;
+        }
+    }
+
     [ComImport]
     [Guid("00021401-0000-0000-C000-000000000046")]
     private class ShellLink { }