Sync from GitHub main: v0.1.1 + v0.1.2 + wiki sync (#3)

src/WebhookServer.Core/Ipc/AdminProtocol.cs

@@ -26,6 +26,7 @@ public static class AdminOps
     public const string ListBackups = "list-backups";
     public const string RestoreBackup = "restore-backup";
     public const string ImportConfig = "import-config";
+    public const string CreateCheckpoint = "create-checkpoint";
 }
 
 public sealed class BackupEntry
@@ -33,6 +34,7 @@ public sealed class BackupEntry
     public string FileName { get; set; } = "";
     public DateTimeOffset SavedAt { get; set; }
     public long SizeBytes { get; set; }
+    public string? Description { get; set; }
 }
 
 public sealed class RestoreBackupArgs
@@ -40,6 +42,11 @@ public sealed class RestoreBackupArgs
     public string FileName { get; set; } = "";
 }
 
+public sealed class CreateCheckpointArgs
+{
+    public string? Description { get; set; }
+}
+
 public sealed class AdminRequest
 {
     [JsonPropertyName("op")] public string Op { get; set; } = "";