feat(web): frontend foundation — Tailwind terminal theme, Query, Router, Zustand + live booth screen

Add tailwindcss (Bloomberg-terminal theme in index.css), @tanstack/react-query +
react-router, zustand, and Radix primitives. Router with role-guarded routes;
QueryClient wrapping the existing apiFetch; a small Zustand live store fed by a
/api/ws client that invalidates Query caches. Booth screen: live occupancy gauge
+ streaming entry/exit/payment feed. Vite proxies the WS upgrade.

Note: BoothScreen references the pay/exit modal + active-sessions panel added in
following commits; final HEAD builds.

apps/web/src/main.tsx

@@ -1,5 +1,6 @@
 import { StrictMode } from "react";
 import { createRoot } from "react-dom/client";
+import "./index.css";
 import { App } from "./App.js";
 
 const rootEl = document.getElementById("root");