fix(gateway): satisfy MCP app backend gates

src/boards/board-store.ts

@@ -30,7 +30,7 @@ export type BoardWidgetMcpAppDocument = {
   declaredTools: string[];
   interactive: boolean;
 };
-export type BoardWidgetDocument = BoardWidgetHtmlDocument | BoardWidgetMcpAppDocument;
+type BoardWidgetDocument = BoardWidgetHtmlDocument | BoardWidgetMcpAppDocument;
 
 export interface BoardStore {
   getSnapshot(sessionKey: string): BoardSnapshot;

src/gateway/methods/core-descriptors.since.test.ts

@@ -27,6 +27,7 @@ const CURRENT_TRAIN_METHODS = [
   "agents.workspace.get",
   "audit.list",
   "audit.activity.list",
+  "board.widget.appView",
   "tts.speak",
   "environments.list",
   "environments.status",