Offline editing and portable workspace backups

Reopen synchronized documents offline and export a verifiable workspace archive of Markdown and original Assets.

Letter.md now keeps more of the workspace useful when the network is unreliable and makes the full content set easier to take with you.

What changed

Reopen previously synchronized documents while offline.
Keep local edits durable and synchronize them after the connection returns.
Export a verifiable ZIP containing folders, Markdown, Frontmatter, tags, internal links, and original Assets.
Inspect an archive before restoring it.
Refuse incomplete or tampered backups without importing partial content.

Offline access depends on the document having synchronized successfully on that device at least once.