fix(build): switch from umd to cjs format to support dual entry points

Vite does not allow multiple entry points with umd/iife output formats.
Switching to es+cjs enables the private/ sub-package build.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

package.json

@@ -6,19 +6,19 @@
   "publishConfig": {
     "registry": "https://nexus.xuqinmin.com/repository/npm-hosted/"
   },
-  "main": "dist/index.umd.js",
+  "main": "dist/index.cjs.js",
   "module": "dist/index.es.js",
   "types": "dist/index.d.ts",
   "exports": {
     ".": {
       "types": "./dist/index.d.ts",
       "import": "./dist/index.es.js",
-      "require": "./dist/index.umd.js"
+      "require": "./dist/index.cjs.js"
     },
     "./private": {
       "types": "./dist/private/index.d.ts",
       "import": "./dist/private/index.es.js",
-      "require": "./dist/private/index.umd.js"
+      "require": "./dist/private/index.cjs.js"
     }
   },
   "files": [

package.private.json

@@ -6,14 +6,14 @@
   "publishConfig": {
     "registry": "https://nexus.xuqinmin.com/repository/npm-hosted/"
   },
-  "main": "dist/private/index.umd.js",
+  "main": "dist/private/index.cjs.js",
   "module": "dist/private/index.es.js",
   "types": "dist/private/index.d.ts",
   "exports": {
     ".": {
       "types": "./dist/private/index.d.ts",
       "import": "./dist/private/index.es.js",
-      "require": "./dist/private/index.umd.js"
+      "require": "./dist/private/index.cjs.js"
     }
   },
   "files": [

vite.config.ts

@@ -11,7 +11,7 @@ export default defineConfig({
         'private/index': resolve(__dirname, 'src/private/index.ts'),
       },
       name: 'XuqmH5SDK',
-      formats: ['es', 'umd'],
+      formats: ['es', 'cjs'],
       fileName: (format, entryName) => `${entryName}.${format}.js`,
     },
     rollupOptions: {