feat: add cdn packages for iife builds

packages/cdn/vite.config.js

@@ -0,0 +1,42 @@
+// @ts-nocheck
+import { dirname, resolve } from 'path'
+import { fileURLToPath } from 'url'
+import { defineConfig } from 'vite'
+import cssInjectedByJsPlugin from 'vite-plugin-css-injected-by-js'
+
+const __dirname = dirname(fileURLToPath(import.meta.url))
+
+/**
+ * CDN IIFE builds for page-agent
+ *
+ * Build targets (via --mode):
+ * - demo: page-agent.demo.js with auto-init and built-in API
+ * - full (default): page-agent.js exposes PageAgent class only
+ */
+export default defineConfig(({ mode }) => {
+	const isDemo = mode === 'demo'
+	const entry = isDemo ? resolve(__dirname, 'src/demo.js') : resolve(__dirname, 'src/full.js')
+	const fileName = isDemo ? 'page-agent.demo' : 'page-agent'
+
+	return {
+		plugins: [cssInjectedByJsPlugin({ relativeCSSInjection: true })],
+		publicDir: false,
+		esbuild: {
+			keepNames: true,
+		},
+		build: {
+			lib: {
+				entry,
+				name: 'PageAgent',
+				fileName: () => `${fileName}.js`,
+				formats: ['iife'],
+			},
+			outDir: resolve(__dirname, 'dist'),
+			emptyOutDir: !isDemo, // only empty on first build (full)
+			minify: false,
+		},
+		define: {
+			'process.env.NODE_ENV': '"production"',
+		},
+	}
+})