Portable IVVI Archive Export and Better Desktop File Import

🔄 Improvements

• Improved desktop file import flow from the native Electron menu, so files now open in the correct application window instead of randomly appearing elsewhere
• Enhanced IVVI archive handling for smoother export and import of maps with attachments
• Improved support for transferring complete maps between devices and users without losing linked assets

✨ New Features

• Added portable .ivvi.zip archive export and import support
  • Maps can now be exported together with images, audio, thumbnails, and presentation attachments
  • Imported archives automatically restore all supported attachments into a working map
  • Supports .ivvi, .ivvi.zip, and .zip import flows
  • Demo video

🛠 Fixes

• Fixed: Native desktop file import from the Electron menubar could open in the wrong window or attach the import flow to another map window

And other improvements