Fix demo because of new default panel (#29279)

demo/src/ha-demo.ts

@@ -9,11 +9,14 @@ import { selectedDemoConfig } from "./configs/demo-configs";
 import { mockAreaRegistry } from "./stubs/area_registry";
 import { mockAuth } from "./stubs/auth";
 import { mockConfigEntries } from "./stubs/config_entries";
+import { mockDeviceRegistry } from "./stubs/device_registry";
 import { mockEnergy } from "./stubs/energy";
 import { energyEntities } from "./stubs/entities";
 import { mockEntityRegistry } from "./stubs/entity_registry";
 import { mockEvents } from "./stubs/events";
+import { mockFloorRegistry } from "./stubs/floor_registry";
 import { mockFrontend } from "./stubs/frontend";
+import { mockLabelRegistry } from "./stubs/label_registry";
 import { mockIcons } from "./stubs/icons";
 import { mockHistory } from "./stubs/history";
 import { mockLovelace } from "./stubs/lovelace";
@@ -60,6 +63,9 @@ export class HaDemo extends HomeAssistantAppEl {
     mockPersistentNotification(hass);
     mockConfigEntries(hass);
     mockAreaRegistry(hass);
+    mockDeviceRegistry(hass);
+    mockFloorRegistry(hass);
+    mockLabelRegistry(hass);
     mockEntityRegistry(hass, [
       {
         config_entry_id: "co2signal",

demo/src/stubs/frontend.ts

@@ -27,4 +27,25 @@ export const mockFrontend = (hass: MockHomeAssistant) => {
     // eslint-disable-next-line @typescript-eslint/no-empty-function
     return () => {};
   });
+  hass.mockWS(
+    "frontend/subscribe_system_data",
+    (_msg, currentHass, onChange) => {
+      onChange?.({
+        value: currentHass.systemData,
+      });
+      // eslint-disable-next-line @typescript-eslint/no-empty-function
+      return () => {};
+    }
+  );
+  hass.mockWS("labs/subscribe", (_msg, _currentHass, onChange) => {
+    onChange?.({
+      preview_feature: _msg.preview_feature,
+      domain: _msg.domain,
+      enabled: false,
+      is_built_in: true,
+    });
+    // eslint-disable-next-line @typescript-eslint/no-empty-function
+    return () => {};
+  });
+  hass.mockWS("repairs/list_issues", () => ({ issues: [] }));
 };

demo/src/stubs/template.ts

@@ -7,8 +7,18 @@ export const mockTemplate = (hass: MockHomeAssistant) => {
     })
   );
   hass.mockWS("render_template", (msg, _hass, onChange) => {
+    let result = msg.template;
+    // Simple variable substitution for demo purposes
+    if (msg.variables) {
+      for (const [key, value] of Object.entries(msg.variables)) {
+        result = result.replace(
+          new RegExp(`\\{\\{\\s*${key}\\s*\\}\\}`, "g"),
+          String(value)
+        );
+      }
+    }
     onChange!({
-      result: msg.template,
+      result,
       listeners: { all: false, domains: [], entities: [], time: false },
     });
     // eslint-disable-next-line @typescript-eslint/no-empty-function