feat: Hammer Dashboard with sidebar navigation (HQ-21)

- Add React Router with sidebar layout (DashboardLayout)
- Queue is now a routed page at /queue
- Chat placeholder page at /chat
- Admin page accessible from sidebar
- Dark sidebar with amber accent for active nav
- Updated CORS and auth to support dash.donovankelly.xyz
- Renamed to Hammer Dashboard

backend/src/index.ts

@@ -52,7 +52,7 @@ ensureAdmin().catch(console.error);
 const app = new Elysia()
   .use(
     cors({
-      origin: ["https://queue.donovankelly.xyz", "http://localhost:5173"],
+      origin: ["https://dash.donovankelly.xyz", "https://queue.donovankelly.xyz", "http://localhost:5173"],
       credentials: true,
       allowedHeaders: ["Content-Type", "Authorization", "Cookie"],
       methods: ["GET", "POST", "PUT", "PATCH", "DELETE", "OPTIONS"],