handle redacted messages more gracefully

lib/models/content/message.dart

@@ -10,7 +10,7 @@ part "message.g.dart";
 @Freezed(unionKey: "msgtype", fallbackUnion: "default")
 abstract class MessageContent extends Content with _$MessageContent {
   MessageContent._();
-  factory MessageContent({required String body}) = UnknownMessageContent;
+  factory MessageContent({String? body}) = UnknownMessageContent;
 
   @FreezedUnionValue("m.text")
   factory MessageContent.text({

lib/widgets/renderers/message.dart

@@ -276,11 +276,20 @@ class MessageRenderer extends ConsumerWidget {
                             ],
                           ],
                         ),
-                        MessageContent(:final body) => Row(
+                        MessageContent(:final body) =>
+                          body == null
+                              ? Text(
+                                  "This message is redacted",
+                                  style: errorStyle,
+                                )
+                              : Row(
                                   spacing: 8,
                                   mainAxisSize: .min,
                                   children: [
-                            Text("Unknown message type:", style: errorStyle),
+                                    Text(
+                                      "Unknown message type:",
+                                      style: errorStyle,
+                                    ),
                                     Text(body),
                                   ],
                                 ),