feat(admin): scaffold Vite+React admin workspace

apps/admin/vite.config.ts

@@ -0,0 +1,7 @@
+import { defineConfig } from 'vite';
+import react from '@vitejs/plugin-react';
+
+export default defineConfig({
+  plugins: [react()],
+  server: { host: true, port: 5174 },
+});