Export save turns the whole save into one code (gzip + base64url
behind a DEADHEAD1. prefix) to copy or share as a file; Import save
takes a pasted code or a file, migrates and validates it, and replaces
the company after confirmation. A bad code is refused and changes
nothing. These replace the backup code. Debug info now gives the save
id, save version and storage type.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
