Put your Web Label Designer HTML file here, named exactly:

    label-designer.html

This is the single-file HTML you already have (the one you shared). The build
uses YOUR pristine copy, so nothing is lost or retyped. build.sh runs
patch_html.py which reads source/label-designer.html and produces
wwwroot/index.html with:
  - the three CDN libraries repointed to the bundled offline copies, and
  - the native printing bridge injected.

Your original file is never modified.
