webui: Add empty conversation demo
diff --git a/webui/src/web-components/demo/mocks/handlers.ts b/webui/src/web-components/demo/mocks/handlers.ts
index c112efd..21bacd7 100644
--- a/webui/src/web-components/demo/mocks/handlers.ts
+++ b/webui/src/web-components/demo/mocks/handlers.ts
@@ -3,10 +3,13 @@
 
 // Mock state updates for long-polling simulation
 let currentState = { ...initialState };
-const messages = [...initialMessages];
+const EMPTY_CONVERSATION =
+  new URL(window.location.href).searchParams.get("emptyConversation") === "1";
 const ADD_NEW_MESSAGES =
   new URL(window.location.href).searchParams.get("addNewMessages") === "1";
 
+const messages = EMPTY_CONVERSATION ? [] : [...initialMessages];
+
 export const handlers = [
   // Unified state endpoint that handles both regular and polling requests
   http.get("*/state", async ({ request }) => {