feat(releases): add SelfUpdater.HandleReplaceSelfAsync

src/ClaudeDo.Releases/SelfUpdater.cs

@@ -56,4 +56,40 @@ public static partial class SelfUpdater
             InstallerAsset: match.Asset,
             ChecksumsAsset: checksums);
     }
+
+    public static async Task<bool> HandleReplaceSelfAsync(
+        string oldPath,
+        string currentExePath,
+        Func<string, bool> launchProcess,
+        int maxWaitMs = 5000)
+    {
+        var deadline = DateTime.UtcNow.AddMilliseconds(maxWaitMs);
+        while (DateTime.UtcNow < deadline)
+        {
+            try
+            {
+                if (File.Exists(oldPath))
+                {
+                    File.Delete(oldPath);
+                }
+                break;
+            }
+            catch (IOException)
+            {
+                await Task.Delay(100);
+            }
+            catch (UnauthorizedAccessException)
+            {
+                await Task.Delay(100);
+            }
+        }
+
+        if (File.Exists(oldPath))
+        {
+            return false;
+        }
+
+        File.Copy(currentExePath, oldPath, overwrite: false);
+        return launchProcess(oldPath);
+    }
 }