Fix deployed script tag and invalid PWA icons

[aliorhun]

Root cause

The generated Pages artifact contained:

<script defer src="./app.js"><\/script>

instead of a real HTML closing tag:

<script defer src="./app.js"></script>

That prevents the app bundle from being parsed/executed correctly, which explains why the page renders but none of the controls work.

The manifest icon warning was a second, independent issue: the previously committed PNG assets were malformed.

Changes

• emit a proper </script> closing tag in dist/index.html
• replace both PWA icons with valid 192x192 and 512x512 PNG files
• add mobile-web-app-capable meta while keeping the Apple meta for compatibility
• remove the old embedded base64 favicon links and use the local PWA icon
• extend offline/PWA verification to:
  • require the exact valid app script tag
  • reject escaped <\/script> output
  • validate PNG signatures, dimensions and every chunk CRC

This is a deployment/runtime hotfix.