Allow users to export and import Picard option profiles as human-readable TOML files, enabling easy sharing on forums and community
  spaces.
  
  Profiles bundle settings overrides together with file naming and tagger scripts, forming self-contained configuration packages for
  specific use cases (e.g., Navidrome, Plex, Jellyfin).
  
  Key requirements:
  
  - TOML format (tomlkit already a dependency, supports comments + multiline strings)
  - "Shareable" flag on options to prevent credential/path leaks in share mode
  - Backup mode for personal migration (includes all profile options)
  - Scripts embedded inline for self-contained profiles
  - Graceful degradation for unknown/renamed options
  - No centralized registry needed — users can paste profiles directly on a forum
  
  Design document: https://github.com/metabrainz/picard/pull/3231