Add mock area registry to demo to fix card picker (home-assistant#20626)

Author: spacegaier

demo/src/ha-demo.ts

@@ -10,6 +10,7 @@ import {
 import { HomeAssistantAppEl } from "../../src/layouts/home-assistant";
 import { HomeAssistant } from "../../src/types";
 import { selectedDemoConfig } from "./configs/demo-configs";
+import { mockAreaRegistry } from "./stubs/area_registry";
 import { mockAuth } from "./stubs/auth";
 import { mockConfigEntries } from "./stubs/config_entries";
 import { mockEnergy } from "./stubs/energy";
@@ -23,10 +24,10 @@ import { mockLovelace } from "./stubs/lovelace";
 import { mockMediaPlayer } from "./stubs/media_player";
 import { mockPersistentNotification } from "./stubs/persistent_notification";
 import { mockRecorder } from "./stubs/recorder";
-import { mockTodo } from "./stubs/todo";
 import { mockSensor } from "./stubs/sensor";
 import { mockSystemLog } from "./stubs/system_log";
 import { mockTemplate } from "./stubs/template";
+import { mockTodo } from "./stubs/todo";
 import { mockTranslations } from "./stubs/translations";
 
 @customElement("ha-demo")
@@ -62,6 +63,7 @@ export class HaDemo extends HomeAssistantAppEl {
     mockEnergy(hass);
     mockPersistentNotification(hass);
     mockConfigEntries(hass);
+    mockAreaRegistry(hass);
     mockEntityRegistry(hass, [
       {
         config_entry_id: "co2signal",