feat: restore the alert feed homepage widget

packages/plugin-sdk/src/testing.ts

@@ -2104,6 +2104,8 @@ export interface RenderedPluginApp {
     hostProtocols: () => string[];
     hostEditorSections: () => string[];
     dashboardCards: () => string[];
+    /** Ids this plugin added to an extension point. */
+    extensions: (pointId: string) => string[];
     settingsComponents: () => string[];
     slot: (slotId: string) => string[];
     actions: () => string[];
@@ -2133,6 +2135,13 @@ export interface RenderedPluginApp {
   renderTab: (type: string, props?: Record<string, unknown>) => HTMLElement;
   renderPanel: (id: string, props?: Record<string, unknown>) => HTMLElement;
   renderDashboardCard: (id: string) => HTMLElement;
+  /** Renders one component of a contributed extension, "view" by default. */
+  renderExtension: (
+    pointId: string,
+    id: string,
+    component?: string,
+    props?: Record<string, unknown>,
+  ) => HTMLElement;
   renderHostEditorSection: (
     id: string,
     props?: Record<string, unknown>,