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>
Adds @xuqm/h5-sdk/private entry point with JSON-based initialization,
feature gating, and error codes for private deployment scenarios.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>