BITESIZE READING LIBRARY — V4.9.0
Direct-ZIP Reading Studio Viewer (offline)

MAIN CHANGE
Import a registered Reading Studio ZIP once using Add Resource. Then open
Teacher Mode, Student Mode, Print Centre, or Reading Toolkit directly from the
Studio card in My Library. Do not select a folder, manually extract a ZIP, or
run a Windows Studio installer.

SUPPORTED PACKAGES
• Reading Studio ZIPs registered with Product Registrar V1.6, including
  bitesize-studio-library.json and matching bitesize-resource.json.
• Earlier registered Reading Studio ZIPs with a valid studio launch manifest
  can also open without a descriptor (subject to file checks).
• Older regular reading-resource packages keep their existing library views.

HOW IT WORKS
• Original purchased/registered ZIP stored by Reading Library in IndexedDB.
• Library-ready imports check descriptor, permanent Product ID, Teacher and
  Student launch paths, file sizes and SHA-256 inventory hashes, with fallback
  hashing in browsers without WebCrypto.
• Studio HTML/JS executes only inside an opaque-origin sandboxed iframe, not
  in the same security context as Library classes, assessments or catalogue.
• Non-executable artwork and stylesheets resolve offline from the ZIP.
• Internal Teacher Guide, print and other HTML pages open in the viewer;
  the Back to Studio button returns to the Studio. PDF files offer a download
  button, with an in-browser preview where the browser supports it.
• Local Studio preferences and progress can be saved on this device through
  a Studio-only storage bridge. These values are not sent to a server.

INSTALLATION / UPGRADE
1. Back up your existing 'Reading Library Files' folder.
2. Extract the UPGRADE_ONLY ZIP into the parent of that folder, allowing
   Windows to merge/replace files. Keep the existing folder at the same path
   and use the same browser profile to preserve imported resources and marks.
3. Open Reading Library with START_READING_LIBRARY.html (Chrome/Edge).
4. Use Add Resource to add a Registrar V1.6 Studio ZIP, or simply open an
   existing imported Studio in My Library.
5. Click Open Teacher Mode or Open Student Mode. No folder picker appears.

IMPORTANT
• The software runs offline. Optional externally hosted web fonts / teacher
  feedback links still need a connection.
• The secure viewer is designed around the supplied Headless Horseman Studio.
  Other bespoke Studios may need compatibility work if they use module imports,
  network fetches, iframes, cross-origin media, or unrestricted window access.
• Browser policy can restrict printing, microphone, file downloads or PDF
  previews inside sandboxed pages. PDFs also have a Download file fallback.
• Do not clear Reading Library site data or move to a different browser
  profile without backing up your resources and assessments.
• V4.9 can import your existing registered ZIP. It does not create the
  Registrar V1.6 descriptor — use Registrar V1.6 to package new products.
• The old INSTALL_STUDIO_WINDOWS helper from V4.8.x is obsolete; the direct
  ZIP Studio viewer does not need it.

VALIDATION PERFORMED
• JavaScript syntax checked with Node.js.
• Registrar V1.6 Headless Horseman ZIP: 101 inventoried files validated,
  including path, byte count and SHA-256 integrity.
• Browser sandbox smoke test: Headless Horseman Teacher Mode rendered with
  its branding and artwork; Teacher Guide opened; Back to Studio worked.
• Reading Library bootstrap displayed without JavaScript page errors.
• A Windows desktop run with the real file:// origin, full import and PDF
  printing workflow is still needed before marking every feature production
  verified. The automated browser test environment blocks local navigation.
