fix(Parser): Add UpdateEngagementPanelContentCommand

This command is sometimes used to open the Transcript panel.

src/parser/classes/commands/UpdateEngagementPanelContentCommand.ts

@@ -0,0 +1,20 @@
+import { YTNode } from '../../helpers.js';
+import { type RawNode } from '../../index.js';
+
+type Identifier = {
+  surface: string,
+  tag: string;
+}
+
+export default class UpdateEngagementPanelContentCommand extends YTNode {
+  static type = 'UpdateEngagementPanelContentCommand';
+
+  public content_source_panel_identifier?: Identifier;
+  public target_panel_identifier?: Identifier;
+
+  constructor(data: RawNode) {
+    super();
+    this.content_source_panel_identifier = data.contentSourcePanelIdentifier;
+    this.target_panel_identifier = data.targetPanelIdentifier;
+  }
+}

src/parser/nodes.ts

@@ -83,6 +83,7 @@ export { default as ContinuationCommand } from './classes/commands/ContinuationC
 export { default as GetKidsBlocklistPickerCommand } from './classes/commands/GetKidsBlocklistPickerCommand.js';
 export { default as RunAttestationCommand } from './classes/commands/RunAttestationCommand.js';
 export { default as ShowDialogCommand } from './classes/commands/ShowDialogCommand.js';
+export { default as UpdateEngagementPanelContentCommand } from './classes/commands/UpdateEngagementPanelContentCommand.js';
 export { default as AuthorCommentBadge } from './classes/comments/AuthorCommentBadge.js';
 export { default as CommentActionButtons } from './classes/comments/CommentActionButtons.js';
 export { default as CommentDialog } from './classes/comments/CommentDialog.js';