feat(web): add login and customer chat demos

Add a responsive login screen using the shared appearance controls and a browser-only customer-service simulator for the chat workspace. Register both routes and include mock media resolution, message sending, and earlier-history loading for interactive verification.

apps/web/src/routes/_app.chats.tsx

@@ -0,0 +1,7 @@
+import { createFileRoute } from "@tanstack/react-router"
+
+import { ChatsDemoPage } from "@/pages/chats-demo-page"
+
+export const Route = createFileRoute("/_app/chats")({
+  component: ChatsDemoPage,
+})

apps/web/src/routes/login.tsx

@@ -0,0 +1,6 @@
+import { LoginPage } from "@/pages/login-page"
+import { createFileRoute } from "@tanstack/react-router"
+
+export const Route = createFileRoute("/login")({
+  component: LoginPage,
+})